The English physician Edward Jenner found that if experimental subject

The English physician Edward Jenner found that if experimental subjects . . .

We have a conditional sentence here, and with conditional sentences, we need to match up the tenses .

1st conditional:
If (simple present) then simple future
If something happens then something else will happen
EXAMPLES:
If Barb sells her car, then she will buy a scooter.
If you touch Neil’s feet, he will cry.

2nd conditional:
If (simple past) then (clause beginning with would)
If something happened then something would happen
EXAMPLES:
If Barb sold her car, then she would buy a scooter.
If you touched Neil’s feet, he would cry.

3rd conditional:
If (past perfect) then (clause beginning with would have)
If something had happened then something would have happened
EXAMPLES:
If Barb had sold her car, then she would have bought a scooter.
If you had touched Neil’s feet, he would have cried.


The English physician Edward Jenner found that if experimental subjects were deliberately infected with cowpox...
Here we have the simple past tense were infected (i.e., 2nd conditional), so the second half of this conditional must have a clause beginning with would

Only answer choice E has this structure.

Answer: E

Cheers,
Brent

Dear NicoleJaneway,

I'm happy to respond. My friend, I commend you for asking a very intelligent and thoughtful question.

In the first sentence about Jenner, the tense in the OA is necessary to indicate a time lag. We don't use this kind of inoculation any more, but if we did, inoculating someone today would mean that this person would become immune, not today, but in a few days. It's not instantaneous, and this time lag is significant to the situation.

Here's the sentence, as you suggest, with the simple past:
The English physician Edward Jenner found that if experimental subjects were deliberately infected with cowpox, which caused only a mild illness, they became immune to smallpox.
Technically, the implication of this is that getting the inoculation of cowpox and becoming immune to smallpox are absolutely simultaneous, as if the inoculation has an instantaneous body-wide effect, quicker than lightning. That's not consistent with the meaning of the situation and not realistic at all. Part of the information in the sentence is the time lag between these two events, and we need the conditional "would become" to indicate this.

In a way, what follows the verb "found" is a kind of indirect speech, and so we need to use the rules for sequences of tenses. Again, these rules would favor the use of the conditional over the simple past.

The other sentence, about Freud, is not quite the same. Here, there was no meaningful time lag. In other words, the Nazi's getting the ransom cash in their hot little hands and the granting of the permission for Freud to leave essentially would be simultaneous. For all intents and purposes, there was no meaningful time lag between these two events, so the verb is under no obligation to hold any kind of information about a time lag. That's why we the simple past is enough here.

My intelligent friend, does this make sense? I will be happy to answer any further questions you have or to listen to any additional points you would like to make.

Mike

Hello Everyone!

Let's take a close look at this question, and see where we can eliminate options quickly to get to the right answer! To get started, here is the original question with major differences between each option highlighted in orange:

The English physician Edward Jenner found that if experimental subjects were deliberately infected with cowpox, which caused only a mild illness, they are immune from smallpox.

A. which caused only a mild illness, they are immune from
B. causing only a mild illness, they become immune from
C. which causes only a mild illness, they are immune to
D. causing only a mild illness, they became immune from
E. which caused only a mild illness, they would become immune to

After a quick glance over each option, a few major differences pop up:

1. immune from / immune to
2. are / become / became
3. caused / causing / causes

Let's start with #1 on our list: immune from vs. immune to. When talking about diseases, we say a person is "immune to" the disease, not "immune from" it. We can eliminate options A, B, and D because they use the incorrect "immune from."

This leaves us with only options C & E, so let's take a closer look at each option:

C. which causes only a mild illness, they are immune to

This option is INCORRECT because the non-underlined part of the sentence uses the past tense verb "found," so we need to use past tense verbs to match. Using the present tense "causes" and "are" aren't consistent with the intended meaning (that all of this happened in the past).

E. which caused only a mild illness, they would become immune to

This is the CORRECT option because it uses consistent past tense verbs throughout, and it uses the correct form of "immune to" to refer to a disease.

There you go! Option E is the correct answer!


Don't study for the GMAT. Train for it.

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning of this sentence is key to solving this question; the intended meaning is that cowpox caused only a mild illness, and Edward Jenner found that if experimental subjects were deliberately infected with cowpox, they would become immune to smallpox.

Concepts tested here: Meaning + Verb Forms + Idioms

• The simple present tense is used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.
• The simple past tense is used to refer to actions that concluded in the past.
• The introduction of the present participle ("verb+ing"- “causing” in this case) after comma generally leads to a cause-effect relationship.
• "would + base form of verb ("become" in this sentence)" is a correct construction for referring to a hypothetical future action.
• "immune from"; remember, "immune to" is the correct, idiomatic construction.

A: This answer choice incorrectly uses the simple present tense verb "are" to refer to a hypothetical future action; remember, "would + base form of verb" is a correct construction for referring to a hypothetical future action, and the simple present tense is used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Further, Option A incorrectly uses the unidiomatic construction "immune from"; remember, "immune to" is the correct, idiomatic construction.

B: This answer choice alters the meaning of the sentence through the phrase "causing only a mild illness"; the use of the "comma + present participle ("verb+ing" - "causing" in this sentence)" construction incorrectly implies that Edward Jenner found that if experimental subjects were deliberately infected with cowpox, and doing so caused only a mild illness, they would become immune to smallpox; the intended meaning is that Edward Jenner found that if experimental subjects were deliberately infected with cowpox, they would become immune to smallpox, and as a separate bit of information, it is mentioned that cowpox caused only a mild illness; remember, the introduction of the present participle ("verb+ing"- “causing” in this case) after comma generally leads to a cause-effect relationship. Further, Option B incorrectly uses the base verb form "become" to refer to a hypothetical future action; remember, "would + base form of verb" is used for referring to a hypothetical future action. Additionally, Option B incorrectly uses the unidiomatic construction "immune from"; remember, "immune to" is the correct, idiomatic construction.

C: This answer choice incorrectly uses the simple present tense verb "are" to refer to a hypothetical future action; remember, "would + base form of verb ("make" in this sentence)" is a correct construction for referring to a hypothetical future action, and the simple present tense is used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.

D: This answer choice alters the meaning of the sentence through the phrase "causing only a mild illness"; the use of the "comma + present participle ("verb+ing" - "causing" in this sentence)" construction incorrectly implies that Edward Jenner found that if experimental subjects were deliberately infected with cowpox, and doing so caused only a mild illness, they would become immune to smallpox; the intended meaning is that Edward Jenner found that if experimental subjects were deliberately infected with cowpox, they would become immune to smallpox, and as a separate bit of information, it is mentioned that cowpox caused only a mild illness; remember, the introduction of the present participle ("verb+ing"- “causing” in this case) after comma generally leads to a cause-effect relationship. Further, Option D incorrectly uses the simple past tense verb "became" to refer to a hypothetical future action; remember, "would + base form of verb" is a correct construction for referring to a hypothetical future action, and the simple past tense is used to refer to actions that concluded in the past.

E: Correct. THis answer choice uses the phrase "which caused only a mild illness" to modify "cowpox", conveying the intended meaning - that Edward Jenner found that if experimental subjects were deliberately infected with cowpox, they would become immune to smallpox, and as a separate bit of information, it is mentioned that cowpox caused only a mild illness. Further, Option E correctly uses the "would + base form of verb ("become" in this sentence)" to refer to a hypothetical future action. Additionally, Option E correctly uses the idiomatic construction "immune to".

Hence, E is the best answer choice.

To understand the concept of "Simple Tenses" on GMAT, you may want to watch the following video (~2 minutes):



To understand the concept of "Comma Plus Present Participle for Cause-Effect on Relationship" GMAT, you may want to watch the following video (~2 minutes):



All the best!
Experts' Global Team

Hi Mike! Hope you've been well.

I thought it might be worthwhile clarifying your comment here, because it might sound like a statement of a general rule. It can definitely sometimes be correct to say "immune from". In a legal context, it is the only correct idiom:

"In Country X, diplomats are immune from prosecution for minor offenses"

Here, it would not be idiomatic to say "immune to". In the question in the original post above though, when talking about infection or disease, "immune to" is always correct. In other situations, I think either usage can be fine. Googling quickly, I saw a headline that read something like "Wall Street is not immune from the effects of the financial crisis", and there it seems to me "immune to" and "immune from" would both be acceptable.

Hey mikemcgarry,

Thank you for the detailed explanation of the question! Follow up query: isn't the past tense "they became immune" acceptable in this sentence? Because this research took place in the past, this situation is not hypothetical (necessitating the subjunctive), but rather conditional.

If he infected subjects with cowpox (and he did), then the subjects became immune to smallpox.

Here's a similar example:



The OA is (A) because, from a historically factual standpoint, Freud was and was always going to be allowed to leave Vienna - the Nazis just wanted the ransom first.

In our example with Jenner, of course, "would become" in choice (E) is acceptable, and (D) can be ruled out because of the unidiomatic use of "immune from." But I would argue that simple past tense in (D) would be preferred if not for the idiomatic error later in the sentence.

Imo E
Correct idiom is immune to
This is a conditional sentence so we have to use conditional structure for past .
Example
I am immune to insults or flattery .

Sent from my ONE E1003 using GMAT Club Forum mobile app

hi ameyaprabhu

I am not expert,but let me share my two cents.

By default, which and that
are noun modifiers and shall obey touch rule,
simply meaning the noun they modify must be placed as close as possible.

You may check an article by GMATNinja here

There are few exceptions as mentioned in above post. Do try to search for another
noun for which / that to modify only when closest noun does not make sense as in few OG examples in above post.

Coming to your query, I do not see a reason for which to jump over cowpox and modify experimental subjects.
Here if you read sentence closely - cowpox makes lots more sense to cause mild illness than any other noun.

Let me know if this helps!

Press kudos if you liked my solution!

Usage of IF..THEN clauses -

Note - It is not mandatory to use "then" in an "IF THEN clause".
It can be - If...., then outcome
- If....., outcome.
- Outcome, If.....

Now coming to the main point-

1. IF CLAUSE --- SIMPLE PRESENT = THEN CLAUSE --- SIMPLE PRESENT OR SIMPLE FUTURE

2. IF CLAUSE --- SIMPLE PAST = THEN CLAUSE --- SIMPLE PAST OR WOULD + VERB

3. IF CLAUSE --- PAST PERFECT = THEN CLAUSE --- WOULD HAVE + VERB

Hope it helps.

My post seems to be out of the subject discussed.

But I've found some useful article about usage of "Immune to" or "Immune from"?
and decided to share https://www.merriam-webster.com/words-at-play/immune-to-vs-immune-from

"Immune to" or "Immune from"?
Either way, it's best to wash your hands.

When it comes to language, no one is immune to making mistakes, and unfortunately, when we make mistakes, none of us are immune from criticism.

And there are questions to which we have no immunity, like whether immune should be followed by to or from.

Immune has a number of meanings, including "free or exempt" and "marked by protection":

As long as the Roth has been open for at least five years prior to your death, the money in that account is immune from federal income taxes.
— Wendy Connick, Associated Press, 14 Sept. 2017

For the first time in its history, the Court declares an entire class of offenders immune from a noncapital sentence using the categorical approach it previously reserved for death penalty cases alone.
— Justice Clarence Thomas, in Graham v. Florida, 17 May 2010

In medical contexts, immune means "having a high degree of resistance to a disease or the effects of a drug or chemical":

The idea is that when the genetically engineered mice mate with the native mice, their offspring would also be immune to Lyme disease. Over time, this would reduce the prevalence of the disease.
— Christina Quinn, in PBS Newshour, 12 Sept. 2017

The traditional advice given by usage commentators is that you become immune to a disease or a drug, as in the above examples, but immune from something when the object is some kind of obligation or duty, such as taxation, or something that can happen to you, such as prosecution. (In Latin, immunis means "exempt from public service.")

Some commentators recommend determining the appropriate preposition based on the relationship between the affecting thing and the object being affected. As Bryan Garner explains in Modern American Usage, "What you’re immune from can’t touch you; what you’re immune to may touch you, but it has no effect."

So if you are immune from prosecution, the prosecutor cannot go after you; if you are immune to a suitor's charms, the suitor can keep wooing you, but it would be to no avail. A person immune from criticism cannot be criticized; a person immune to criticism can be criticized but doesn't let the criticism bother them.

Actual usage tends to be somewhat murkier, particularly when the affecting thing is expressed in abstract or figurative language:

Williams said Kansas is not immune to earthquakes. There are fault lines near Manhattan, and the eastern half of the state sits between two major mid-continental faults…
— William Klusener, _The Morning Sun _(Pittsburg, Kansas), 9 Nov. 2011

Liberals are not immune from temptation and hubris even when they mouth correct sentiments.
— National Review, 2 Sept. 2013

And yet, because they admit to being partial inventions, these films evade charges of distortion and falsification, and are immune to any legal consequences that might follow.
— Sean Wilentz, The New Republic, 1 Feb. 1993

Up went his temperature; off to bed I packed him; and in a week he was all right again, and absolutely immune from typhoid for the rest of his life.
— George Bernard Shaw, The Doctor's Dilemma, 1906

Since the very nature of the word implies a kind of separation or distancing—either from disease or trouble—it's understandable that from is sometimes preferred. Are there other options? Once in a while we run into the occasional immune against, but this is rare:

Third, the fortunate ones of us who do recover develop antibodies that leave us immune against a recurrence of the disease for a long time
— Jared Diamond, Guns, Germs, and Steel, 1997

We hope we've helped bolster your immunity to this problem. (Regardless, our best advice is to avoid the need to be immune from prosecution in the first place.)

In summary: If you're immune from something, it cannot reach you. If you're immune to something, it will not affect you.

Either would work, actually, and the more natural choice is the present tense "causes."

Notice that the question writer used the less natural, and even debatably incorrect, past tense "caused" in the correct answer to make it less obviously correct.

Himanshuv0

Yeah, that OG explanation is not very good. The team that writes the explanations is clearly not on the same level as the team that produces the questions.

Since B and D have other flaws, it’s not necessary that the -ing modifier be incorrect. “Fake” splits are common in SC! The -ing modifier makes a fair amount of sense here, but it does create a slight difference in meaning. The noun modifier in A/C/E tells us that cowpox causes a mild infection in general. So the idea is that we can infect someone with cowpox (not so bad) to prevent smallpox (a worse disease). Since B/D uses an adverbial modifier, these sentences are saying that the act of infecting someone deliberately with cowpox causes only a mild infection. This leaves open whether this is true of all cases of cowpox, or only those resulting from deliberate infection. That’s not a huge flaw in B/D, but I believe that’s what the OG explanation is trying to address.

The verb "were infected" is in fact considered simple past. Note that it's a passive verb: some unknown experimenters infected the subjects with small pox, and the subjects were infected by those experimenters.

Since the experimental subjects were acted on by the verb, we need to use the passive voice. And "was/were + past participle" is the correct form for the passive simple past.

I hope that helps!

Hi krndatta, "present participial" phrase (causing...in this case) preceded by a comma, generally modifies the subject of the preceding clause.

In this case, the subject of the preceding clause is experimental subjects. Hence, B and D convey the sub-optimal meaning that experimental subjects caused only a mild illness (while as per the intended meaning, "cowpox" caused only a mild illness).

Following construct would be better (though would slightly change the meaning):

if cowpox were deliberately injected into experimental subjects, causing only a mild illness...

p.s. Our book EducationAisle Sentence Correction Nirvana discusses "present participial phrases", their application and examples in significant detail. If you or someone is interested, PM me your email-id; I can mail the corresponding section.

Verb-ing after a comma at the end of the clause modifies the entire previous clause. Hence, we cannot consider that it is modifying just cowpox.
Besides, the non underlined part is using the second conditional (past tense in 'if' clause) so we should use 'would' in 'then' clause.

Also, 'immune to' and 'immune from' are normally used in different contexts (though this wouldn't be the deciding factor):
immune to a disease - not susceptible
immune from punishment - exempt

Answer (E)

This question sounds more like the second conditional which stipulates that when we use simple past in the if clause, then we have to use the modal 'would' in the main clause, subjunctive or no subjunctive.

Since scientific postulates are more of universal facts and not fancies or speculatives, they can even be termed as either zero conditionals or first conditionals.

Look at the following sentences.

1. Scientists conclude that if experimental subjects are deliberately infected with cowpox, they are immune to smallpox. -- Zero conditional

2. Scientists conclude that if experimental subjects are deliberately infected with cowpox, they will be immune to smallpox. -- First conditional

3. Scientists concluded that when experimental subjects were deliberately infected with cowpox, they became immune to smallpox -- A simple indicative clause without any conditional or subjunctive.

4. Scientists concluded that if experimental subjects were deliberately infected with cowpox, they would become immune to smallpox-- Second conditional

As seen above, if we are going to include an 'if' in the subordinate clause, then the modal 'would' becomes imperative in the main clause. Therefore, Ans E is okay.

Hi skycastle19, your understanding in this regard is correct!