This is from OG12. OE is:
Agreement; Rhetorical construction
When a number of plural nouns appear in phrases between a singular subject and the verb, it can be easy to overlook the true subject of the verb. Here, judges, partners, firms, and women all occur between the singular subject, proportion, and the verb, which should also be singular, has risen. Concise expression is particularly important in a long construction; to a comparable extent may be more concisely expressed as comparably.
A Plural verb, have risen, does not agree with the singular subject, proportion.
B Have risen does not agree with proportion; here, women applies only to judges, not to partners at major law firms.
C Correct. In this sentence, has risen agrees with proportion, and comparably is more
concise than to a comparable extent. The modifying clause who are women follows
(1) judges and (2) partners at major law firms as closely as is possible given the content of the sentence; this positioning has the virtue of being clear in its meaning.
D The contrast has already been introduced by
despite, so the addition of
yet is illogical and ungrammatical;
to a comparable extent is wordy.
E Despite introduces the contrast; adding yet is illogical and results in an ungrammatical construction.
The correct answer is C.