Some patients who do not respond to therapies for depression may simpl

A -- having, for example been prescribed a drug as a dosage too low to be effective or having been ...PARALLEL AND PARTICIPLE PHRASE CONTUNING THE COMMA..CORRECT
B -- having, for example, a drug prescription that was ineffective because the dosage was too low, or being
BEING is ICORRRECT..HAS TO BE PAST PERFECT CO
C -- as, for example, having too low of a dosage of prescribed drug for it to be effective, or being
SENTENCE CANNOT START WITH AS AFTER COMMA
D -- when they have, for example, been prescribed too low a drug dosage for it to be effective, or were
WHEN CANNO START A SETNCE ATER COMMA
E -- for example, when they have a drug prescription with a dosage too low to be effective, or been
UNPARALLEL

Here is my explanation with some additional concepts:

A. having, for example, been prescribed a drug at a dosage too low to be effective or having been

Statements beginning with 'having' are tricky and you have to be extra careful using them. Generally these statements refer to an event that has happened prior to another event mentioned in the sentence. Now lets move on to the first answer choice: the 2 events 'drug prescription' and 'patients being taken off a drug too soon' happened before the event 'when some patients did not respond to therapies for depression';

Therefore you can also read the sentence as Having, for example, been prescribed a drug at a dosage too low to be effective or having been taken off a drug too soon, Some patients who do not respond to therapies for depression may simply have received inadequate treatment.

So this answer choice looks good to me. Moreover the parallelism between 'having' clauses maintains the sanctity of the answer choice. Additionally, also remember that a verb form of a word is always preferred over the noun form or adjective form. Therefore, 'prescribe' as a verb is preferred over 'prescription' as a noun or 'prescribed' as an adjective.

B. having, for example, a drug prescription that was ineffective because the dosage was too low, or being

Problem with this statement is that there is no parallelism between clauses beginning with 'having' and 'being'; also refer the usage of being as mentioned here by eGMAT https://gmatclub.com/forum/correct-usage-of-being-123156.html

C. as, for example, having too low of a dosage of a prescribed drug for it to be effective, or being

Again the same problem as that of option B. Moreover the problem is compounded with the use of 'as having'...wierd!!

D. when they have, for example, been prescribed too low a drug dosage to be effective, or were

Always be careful when you see 'when' , for 'when' should preferably refer to some event in time. Here there is none!! In addition to that, the parallelism between 'when' and 'were' is WRONG.

E. for example, when they have a drug prescription with a dosage too low to be effective, or been

Similar explanation as that of D, additionally look at the weird parallelism between the two clauses.

I hope my explanation helped.

I ruled out A as:
I thought since the sentence is giving two examples 'having been prescribed ..' and 'having been taken off...' both should follow after 'for example'. So it should look like - "for example, having been prescribed a drug as a dosage too low to be effective or having been"

How can I make myself familiar with this kind of structure.

Is E incorrect because -
'have a drug prescription (simple present/active)' and 'have been taken off (present perfect/passive) are not parallel. Which one is a bigger deal tense or voice change?

Is this an OG problem?

Experts pls help

Hi Nina1987, for example is basically used as a Parenthetical Expression here. Such constructs give a slight pause/interrupt the main clause. Some example:

Usain Bolt, by all measures, is the best sprinter the world has ever seen.

Peter, in all likelihood, will join Wharton.

I believe this is the reason why you chose E, because all other options use Parenthetical Expression.


Neither tense nor voice is a big deal, in the sense that different parts of the sentence can be in different tense/voice. It depends on the context. An easy way to eliminate E is because it seems to suggest that prescription has a low dosage (while in reality, drug has a low dosage).

A. having, for example, been prescribed a drug at a dosage too low to be effective or having been. Correct parallalism
B. having, for example, a drug prescription that was ineffective because the dosage was too low, or being. How can a drug prescription be ineffective? Also, 'being' is generally wrong on GMAT
C. as, for example, having too low of a dosage of a prescribed drug for it to be effective, or being as having X is not parallel with as having y. Also, 'being' is generally wrong on GMAT
D. when they have, for example, been prescribed too low a drug dosage to be effective, or were or preceeded by ',' must be followed by an independent sentence
E. for example, when they have a drug prescription with a dosage too low to be effective, or been or preceeded by ',' must be followed by an independent sentence

A is the answer

B is WRONG because an ability can't be "accurate", an ability is not something that can be compared quantitatively to a "true" or "target" mark of some sort. by contrast, models (which can approximate true quantitative phenomena), shots at a target (which can come close to the center of the target), and so on can be "accurate".

so yes, (c) changes the meaning, i guess, but it's a desirable change of meaning - because it takes the sentence from a nonsense phrasing to a phrasing that actually makes sense.

Hey, I am confused between options A and D. To me, both the options look grammatically parallel.
A -> having been prescribed || having been taken
D -> have been prescribed || were taken off

Given my understanding, I believe the above elements are parallel in option D because different tenses can be parallel to each other, as in above present perfect and past tense. Request, if you could elaborate all the errors in D and throw some light on how A and D are different.

Thanks!

"may have done" show a chance that something could have happened in the past.

comma+having done show an action which happen before the main action in the main clause. action in the main clause can be in present simple, in simple past or can be a chance in the past presented by "may have done".

the critical logic here is that "prescribing and taking off..." must happen before "may have received" for the sentence to be logical. only choice A show this sequence.

Some patients who do not respond to therapies for depression may simply have received inadequate treatment, having, for example, been prescribed a drug at a dosage too low to be effective or having been taken off a drug too soon.

A. having, for example, been prescribed a drug at a dosage too low to be effective or having been
Having been prescribed or having been taken off..- maintains parallelism.

B. having, for example, a drug prescription that was ineffective because the dosage was too low, or being
Was it the prescription that was ineffective? Nope. The drug was ineffective. The clauses before and after “or '' are not parallel. Eliminate.

C. as, for example, having too low of a dosage of a prescribed drug for it to be effective, or being
Same as B. Eliminate

D. when they have, for example, been prescribed too low a drug dosage to be effective, or were
When- they have been prescribed… or were..
Breaks parallelism. Eliminate

E. for example, when they have a drug prescription with a dosage too low to be effective, or been
Same as B. It is not the prescription but the drug dosage that is ineffective. Eliminate.

Option A resolves all these errors and is the best choice.

Hi Experts, AndrewN MartyTargetTestPrep

In Option D, Please advise why the tense usages are incorrect. Please can you also advise the usage of "having" in Option A.

Thanks

Take another look at the relevant portion of (D):


The verb tense here changes from present perfect, "have been" to the past "were." I don't see any good reason to change the tense, given that we're talking about two instances of inadequate treatment, particularly when (A) has the clean and consistent construction, "having been prescribed" or "having been taken off."

But is it definitively wrong to change the tenses? I don't think so.

Fortunately, there's a big logical problem with (D). The clause "when they were prescribed too low a dose to be effective," makes it sound like "they" aren't effective. But that doesn't make any sense, as "they" seems to refer to "patients." I'm not sure what an "ineffective patient" is, but I'm confident that this isn't what the writer had in mind.

Contrast that with (A), in which "too low to be effective" is clearly referring to the "dosage." Way more logical.

Taken together, (A) is clearly better, even if (D) doesn't have an ironclad grammatical error.

I hope that helps!

Hi there

A] 'having been'' refers to patients. Isn't a noun modifier here?
How is this modifying the verb ''have received''?

B] if parallelism in A] is right. Why not in B] then?

D] is the usage of past tense 'were' right here? if we ignore that 'when' is used incorrectly

Anytime you see an "-ing" modifier following a full clause and a comma, you should assume that the -ing is describing the entire previous clause. When the -ing represents an action that some entity performed, usually it's referring to the subject of the previous clause, even though it's not actually modifying that subject directly.

Put another way, "having been" technically modifies the entire previous clause, but it's clearly giving info about the subject of that clause, "some patients."


The tense in (B) doesn't make sense. If the patients are "being" taken off a drug, it sounds as though they're still in the process of weaning off the medication. If the prescription "was" ineffective in the past, it can't be a current process that's responsible for that, right?


Take a look at this post and let us know if you still have questions about the usage in (D).

I hope that helps!

answer (D) provides:

“Some patients who do not respond to therapies for depression may simply have received inadequate treatment, when they have, for example, been prescribed too low a drug dosage to be effective, or were taken off a drug too soon.”

There exists a problem with the general sentence structure. When you read version (D), it sounds like a run-on. Grammatically, however, the sentence is fine. The issue lies in the meaning attached to the subordinate conjunction “when” and the clause that follows it.

In general, we use the subordinate conjunction “when” and the clause that follows to talk about a subsidiary action or event that occurs at the same time with or immediately after the main sentence.

In other words, the use of “when” and the following clause implies that the events happened alongside the “receive(ing) of inadequate treatment.”

This is the wrong meaning. Instead, both being prescribed the drug at a low dose and being taken off of the drug too soon are EXAMPLES of the inadequate treatment .

If we rearrange the sentence and omit the parenthetical:

(D) “When they have….been prescribed too low a drug dosage….or were taken off a drug too soon, some patients….may have received inadequate treatment.”

The sentence implies that once they were prescribed or were taken off the drug, at that point in time, the patients received the bad treatment.

However, the author is trying to say the two events are EXAMPLES of the “inadequate treatment” that these patients may have received.

Analogous example:
Ex: “The game ended when the referee blew his whistle.”

Meaning: Immediately after the referee blew his whistle, the game was over.

The problem is that in version (D), the author is trying to use this subordinate “when” clause to provide an example of the idea described by the main sentence. This is not what this kind of “when” subordinate clause structure is designed to do.

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Some patients who do not respond to therapies for depression may simply have received inadequate treatment, having, for example, been prescribed a drug at a dosage too low to be effective or having been taken off a drug too soon.

Option elimination -

A. having, for example, been prescribed a drug at a dosage too low to be effective or having been - "having been" construction is used to indicate a past action (with its effect still present) that occurred before another action. So both actions here, "having been prescribed" and " having been taken" (present perfect passive construction) completed in the past that led to the 1st statement, "some patients have received inadequate treatment," are correct sequences of events or parallelism.

B. having, for example, a drug prescription that was ineffective because the dosage was too low or being - a "drug prescription that was ineffective." how can a prescription written on a piece of paper or PDF be ineffective- the drug can be ineffective and not the prescription - wrong meaning.
Moreover, there is an issue from a parallelism standpoint as well. "Having" in part before "or" working as a "gerund" and after "or" we have "being taken" is a passive continuous tense. Not parallel.

C. as, for example, having too low of a dosage of a prescribed drug for it to be effective, or being - same parallelism error "having" is a gerund and "being taken" is a passive continuous verb. Wrong. Moreover, what is "it" referring to? Drug? Dosage? Ambiguous.

D. when they have, for example, been prescribed too low a drug dosage to be effective, or were - "when" time marker and means a specific time, but the intended meaning is "in general" and not at a specific time. Moreover, "have been prescribed" means something started in the past and still continuing. The intended meaning is that this happened in the past, and because of this, we say that the patients received inadequate treatment. Also, there is no specific reason to break parallelism with present perfect before "or" and past tense after "or."

E. for example, when they have a drug prescription with a dosage too low to be effective, or been - the same issue of "when" time marker that limits it to a specific time as against the intended "general concept." Moreover, "have" before "or" is a helping verb to indicate possession. So before "or" we have "have" a drug prescription (noun) and after "or" we have "have been taken" past perfect tense. Ellipsis are applied to the later part and not to the former. Here "have" can be taken for the part after "or" but "been" can't be taken for "have" in the first part. This creates a nonparallel wrong structure.

Shouldn't the for example be in the root phrase here? Low dosage and removing the drug early, both are cited as examples.

I chose option E because of this logic.

@GMATNinja, can you please help?

(E) doesn't work because the parallelism is off: "... when they have (1) a drug prescription with a dosage too low to be effective, or (2) been taken off a drug too soon." In this case, we have a noun (have (1) a drug prescription) and the second part of a verb (have (2) been...), and those things are not parallel.

Also, the "when" is confusing. Does this mean that they received inadequate treatment WHEN they have a drug prescription with a dosage too low to be effective? This makes it sound as though the inadequate treatment and the ineffective dosage or prescription are separate things -- as if the patients received some OTHER inadequate treatment WHILE they were given an ineffective dosage or prescription.

Lastly, in (E), the placement of "for example" makes us think that it applies to the preceding part -- as if receiving inadequate treatment IS an example.

Your concern with (A) is valid and good to think about, but the parallel structure makes it clear enough that both "having been" parts are meant to be examples. The issues with (E) are more significant, so (A) is a better choice.

I hope that helps!