Sentence Correction

Where once the union had acquiesced to the prejudices of its English-speaking members by supporting the imposition of an alien tax on immigrant workers, after 1897 the United Mine Workers made a determined effort to enlist Italians and Slavs in its ranks.
(A) Where once the union had acquiesced to the prejudices of its English-speaking members by supporting
(B) Where once the union acquiesced to it English-speaking members’ prejudice for the support of
(C) While once the union had acquiesced to the prejudices of its English-speaking members in support of
(D) While once the union acquiesced to its English-speaking members’ prejudice in supporting
(E) While once the union had acquiesced to the prejudices of its English-speaking members in its supporting of

Please explain. OA after few explanations

f2001290 wrote:Where once the union had acquiesced to the prejudices of its English-speaking members by supporting the imposition of an alien tax on immigrant workers, after 1897 the United Mine Workers made a determined effort to enlist Italians and Slavs in its ranks.
(A) Where once the union had acquiesced to the prejudices of its English-speaking members by supporting
(B) Where once the union acquiesced to it English-speaking members’ prejudice for the support of
(C) While once the union had acquiesced to the prejudices of its English-speaking members in support of
(D) While once the union acquiesced to its English-speaking members’ prejudice in supporting
(E) While once the union had acquiesced to the prejudices of its English-speaking members in its supporting of

Please explain. OA after few explanations

I think you need "while" instead of "where" to indicate the contrast.

Also, you need the Past perfect "had acquiesced" since the first part
of the sentence happens prior to 1987.

That leaves us with C and E.

E has an awkward "in its supporting of" which is preferred over "in
support of"

Is it C ?

Where is not the correct choice here to bring out the contrast....Hence eliminate Choice A and B....E is too wordy and awkward ("in its supporting of" is awkward)....Amongst C & D....I would go with C....the use of the past perfect tense here is imperative since the two events happened one after the other and not simultaneously....

The OA is A, can anyone comment.

Good question ... bowled over...
Here's what another forum replies to this question:
B - incorrect - changes the meaning of the sentence - illogically suggests that imposition of an alien tax was the reason why the union acknowledged the prejudice of its english-speaking members.

C, D, E - incorrect - use of while wrong

chose A..