Hi iMyself, the short answer is that caused is not used as a verb here, but as a participle.

An easier way would be to do a XYZ Analysis (as per our book Sentence Correction Nirvana). With B, the structure would be:

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but are by a bacterium that dwells in the mucous lining of the stomach.

So, the structure is: C Not X but Y, where C is the structure of the sentence outside the XY deconstruct.

C: Recently physicians have determined that stomach ulcers are
X: caused by stress, alcohol, or rich foods
Y: are by a bacterium that dwells in the mucous lining of the stomach

Since C is outside the XY deconstruct, C must make sense with both X and Y.

i) Is C making sense with X?

Recently physicians have determined that stomach ulcers are caused by stress, alcohol, or rich foods. - Seems fine.

ii) Is C making sense with Y?

Recently physicians have determined that stomach ulcers are are by a bacterium that dwells in the mucous lining of the stomach - Clearly not correct (are is repeated twice).

Since C is not making sense with Y, B is incorrect.

p.s. Our book EducationAisle Sentence Correction Nirvana discusses the framework of XYZ deconstruct, its application and examples in significant detail. If someone is interested, PM me your email-id; I can mail the corresponding section.
_________________

Hi
this question tests your knowledge of parallelism

The correct idiom is "not X but Y". X and Y must be parallel

Note that A and B have a construction "not CAUSED ........ but Y'
If the writer wants to write that way, it should be "not CAUSED X, but CAUSED Y"


In this case, X and Y both have to have a "by" inside them.
The only alternative that has a structure "caused not by X, but by Y" is C

sounds good?

C it is.

Between B and C. C has the correct construction of "not by X, but by Y"
_________________

Is the OA C ?

Idiom, Parallel construction

Not by X, But by Y

caused not by (stress, alcohol, or rich foods), but by (a bacterium that dwells in the mucous lining of the stomach.)

yes C - parallelism "not by x but by Y"

Hey

Answer C is correct.

According to option C the sentence structure is that
Recent physicians have .... are caused NOT X BUT Y.
Here " are caused " is parallel to both X and Y. Hence we need not repeat it at Y.
This structure can also be rephrased as:
Recent physicians have... are NOT X BUT Y.
But in this case "cause" has to be included in both the parts X and Y.

Hope it clarifies.

ksp, thanks for your reply. Just before you wrote, I thought about it and came to the same conclusion:



Thanks again.

Minor clarification - actually the sentence structure is

"caused not by X...., but by Y.."

The word "by" should be on both sides of the comma.

So this is an X&Y Consistency Question (Framework #6).

This question tests parallelism issue. Not ... but idiom.

Straight away C. maintains parallelism.

A. not caused by stress, alcohol, or rich foods, but (but should by followed by "by") Wrong
B. not caused by stress, alcohol, or rich foods, but are by ("are" is extra here) Wrong
C. caused not by stress, alcohol, or rich foods, but by (not by....but by) Correct
D. caused not by stress, alcohol, and rich foods, but (need "by" after "but") Wrong
E. caused not by stress, alcohol, and rich foods, but are by ("are" is extra) Wrong
_________________

I have one question. In option B, is "are" in "but are" used as a verb? If yes, then "not caused (verb)" would be parallel to "but are(verb)" and would be correct.

Please share your thoughts.

Almost anything in a sentence can be made parallel to a similar Parallel Element.

we know by spotting Parallel Markers(here NOT X BUT Y)—words that link or contrast items and that force those items to be parallel

In answer Choice B,

"NOT Caused by.......BUT are by........" is not paralleled

"NOT Caused by......BUT caused by......" is paralleled

"caused NOT by......BUT by......" is paralled

So, Correct Answer is C

The question is totally Parallelism issue. Here the correct answer is C. But, my question is: WHY not B. B makes parallelism to me!
B. NOT (tag)+CAUSED (verb)+by+something....................BUT (tag)+ARE (verb)+by+Something
Indicate parallelism to each other.
Thanks...
_________________

Concept Tested : Parallelism - Not x but y
A. not caused by stress, alcohol, or rich foods, but --> Required Not by X but by Y
B. not caused by stress, alcohol, or rich foods, but are by --> "caused by" is not parallel to "are by" ==> Caused is not a verb
C. caused not by stress, alcohol, or rich foods, but by --> Correct Parallelism
D. caused not by stress, alcohol, and rich foods, but --> Required Not by X but by Y
E. caused not by stress, alcohol, and rich foods, but are by --> Required Not verb/by but verb/by

Is option D wrong because of "and rich foods"? "by" after "but" in option D should be implicit and not necessarily required.

It doesn't matter much whether the disease is caused by the factors individually or severally or by a combination just two. The more important thing is that except C, all others are instant dropouts due to improper correlative parallelism.
_________________

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.

A. not caused by stress, alcohol, or rich foods, but
B. not caused by stress, alcohol, or rich foods, but are by
C. caused not by stress, alcohol, or rich foods, but by
D. caused not by stress, alcohol, and rich foods, but
E. caused not by stress, alcohol, and rich foods, but are by
_________________

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.
A. not caused by stress, alcohol, or rich foods, but - Parallelism issue - ‘caused by stress…” and “a bacterium” are not parallel
B. not caused by stress, alcohol, or rich foods, but are by - “caused by stress” and “are by a bacterium” are not parallel
C. caused not by stress, alcohol, or rich foods, but by - Correct
D. caused not by stress, alcohol, and rich foods, but - “by stress” and “a bacterium” are not parallel. The first is a prepositional phrase; the second is a noun.
E. caused not by stress, alcohol, and rich foods, but are by - “by stress” and “are by a bacterium” are not parallel. The first is a prepositional phrase; the second one starts with a verb


Answer C
_________________

Hello Everyone!

This is a great example of a sentence that focuses on parallelism, so let's dive in! To start, let's take a quick look at the original question, and highlight the main differences in orange:

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.

A. not caused by stress, alcohol, or rich foods, but
B. not caused by stress, alcohol, or rich foods, but are by
C. caused not by stress, alcohol, or rich foods, but by
D. caused not by stress, alcohol, and rich foods, but
E. caused not by stress, alcohol, and rich foods, but are by

After a quick glance over the options, there are a few things we can focus on:

1. not caused / caused not (parallelism/idioms)
2. or / and (meaning/lists)
3. but / but are by / but by (parallelism/idioms)

Since we know this question mainly focuses on parallelism, let's tackle #1 & #3 on our list at the same time. This is the idiom structure we're working with here:

not X, but Y

Both X and Y must be written using parallel structure, including word placement, verb tenses, singular/plural, etc. Since the phrase "caused by" is included in this sentence, we need to be careful to make sure it's included in both X and Y only if it appears after the word "not:"

not caused by X, but caused by Y = PARALLEL
not caused by X, but Y = NOT PARALLEL

caused not by X, but by Y = PARALLEL
caused not by X, but caused by Y = NOT PARALLEL
caused not by X, but Y = NOT PARALLEL

Let's add in the end of the sentence to see which options use parallel structure, and eliminate those that don't:

A. not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach. --> not caused by X, but Y = NOT PARALLEL

B. not caused by stress, alcohol, or rich foods, but are by a bacterium that dwells in the mucous lining of the stomach. --> not caused by X, but are by Y = NOT PARALLEL

C. caused not by stress, alcohol, or rich foods, but by a bacterium that dwells in the mucous lining of the stomach. --> caused not by X, but by Y = PARALLEL

D. caused not by stress, alcohol, and rich foods, but a bacterium that dwells in the mucous lining of the stomach. --> caused not by X, but Y = NOT PARALLEL

E. caused not by stress, alcohol, and rich foods, but are by a bacterium that dwells in the mucous lining of the stomach. --> caused not by X, but are by Y = NOT PARALLEL

There you have it! Option C is correct because it's the only one that uses parallel structure within the idiom "not X, but Y." By focusing on parallelism, you should be able to answer this question pretty quickly!


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