Interesting question, Mahmud6! I had to think about that one a little bit.

When used as a coordinating conjunction, "for" is fairly close in meaning to "because." "While" has a completely different meaning: it introduces a counterpoint, not unlike the word "but." And if it's appropriate to the meaning of the sentence, it's absolutely fine to use both "while" and either "for" or "because":

Charles gained more weight than his wife because he ate nine enormous burritos every morning, while she only ate three.

No problem, right? And even if you replace "because" with "for", it doesn't really change anything:

Charles gained more weight than his wife, for he ate nine enormous burritos every morning, while she only ate three.

For whatever it's worth, I really don't like this particular use of the word "for" -- it sounds pretentious and outdated, at least to my sloppy American ears. But it does appear on the GMAT, unfortunately. Here's an official example: https://gmatclub.com/forum/the-olympic- ... 85874.html
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According to the investigations of physiologists and psychologists,
nervousness has been found to be not an organic disease but a functional one,
which is a critical distinction,
for an organic disease implies impairment of the tissues of an organ,
while a functional disease indicates only a disruption of its role.

The given sentence uses not X but Y idiom where X and Y must be parallel.
Which incorrectly moidifes a functional one therebey changes the intended meaning.
The finding that Nervousness is not X but Y is a critical condition but Given sentence implies that a functional one is a critical distinction.

B. nervousness, found to be an organic disease rather than a functional one, a critical distinction, because an organic disease implies impairment of an organ’s tissues, while a functional disease indicates only a role disruption

a critical distinciton is a misplaced modifier.
There is no verb for subject and there is confusion regarding even subject(Nervousness or finding).

C. it has been found that nervousness is not an organic disease but rather is a functional one; while a functional disease indicates only a disruption of an organ’s role, an organic disease implies impairment of the tissues, a critical distinction

is after rather is incorrectly used disrupting the parallelism in not X but Y idiom.
Critical distinction is once again misplaced improperly.

D. nervousness has been found to be not an organic disease but a functional one; this distinction is critical, for an organic disease implies impairment of the tissues of the organ, while a functional disease indicates only a disruption of its role
(No error.
Nervousness is the subject.
This distinction correctly refers to finding.)

E. nervousness was found to be not an organic disease but a functional one, a critical distinction, since impairment of the tissues of the organ is implied by an organic disease, while a functional disease indicates only a role disruption

critical distinction is misplaced same as in option C.
Passive construction is used in half sentence while active is followed in the end.

IMO the answer is , see my responses against the answers.

According to the investigations of physiologists and psychologists, nervousness has been found to be not an organic disease but a functional one, which is a critical distinction, for an organic disease implies impairment of the tissues of an organ, while a functional disease indicates only a disruption of its role.

A. nervousness has been found to be not an organic disease but a functional one, which is a critical distinction, for an organic disease implies impairment of the tissues of an organ, while a functional disease indicates only a disruption of its role
- modifier issue, which is incorrectly referenced. not reading the rest of the sentence as this is ruled out.

B. nervousness, found to be an organic disease rather than a functional one, a critical distinction, because an organic disease implies impairment of an organ’s tissues, while a functional disease indicates only a role disruption
- this option is off. modifier issues with critical distinction.

C. it has been found that nervousness is not an organic disease but rather is a functional one; while a functional disease indicates only a disruption of an organ’s role, an organic disease implies impairment of the tissues, a critical distinction
- issue with not A but 'rater' B. ruled out.

D. nervousness has been found to be not an organic disease but a functional one; this distinction is critical, for an organic disease implies impairment of the tissues of the organ, while a functional disease indicates only a disruption of its role
- no major issues with this. even though there are multiple parts involved.

E. nervousness was found to be not an organic disease but a functional one, a critical distinction, since impairment of the tissues of the organ is implied by an organic disease, while a functional disease indicates only a role disruption
- again, I think critical distinction has a modifier issue

A. nervousness has been found to be not an organic disease but a functional one, which is a critical distinction, for an organic disease implies impairment of the tissues of an organ, while a functional disease indicates only a disruption of its role --> which wrongly referring to a function one. The whole idea is a critical distinction, not something.

B. nervousness, found to be an organic disease rather than a functional one, a critical distinction, because an organic disease implies impairment of an organ’s tissues, while a functional disease indicates only a role disruption --> verb is missing. nervousness (modifier) (modifier) because.

C. it has been found that nervousness is not an organic disease but rather is a functional one; while a functional disease indicates only a disruption of an organ’s role, an organic disease implies impairment of the tissues, a critical distinction--> parallelism issue.

D. nervousness has been found to be not an organic disease but a functional one; this distinction is critical, for an organic disease implies impairment of the tissues of the organ, while a functional disease indicates only a disruption of its role

Correct

E. nervousness was found to be not an organic disease but a functional one, a critical distinction, since impairment of the tissues of the organ is implied by an organic disease, while a functional disease indicates only a role disruption --> whose role disruption?
also these two sentence are not parallel.
impairment of the tissues of the organ is implied by an organic disease
a functional disease indicates only a role disruption

Is the usage of both coordinating conjunction (for) and subordinating conjunction (while) in a single sentence correct? Somehow, I came to know that it is not correct.

.......... for an organic disease implies impairment of the tissues of the organ, while a functional disease indicates only a disruption of its role
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Hi Everybody,

Why would "a critical distinction" is a misplaced modifier in answers B and E?

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