AbeNeedsAnswers wrote:Unlike the virginal, whose single set of strings runs parallel to the front edge of the instrument, the harpsichord's several sets of strings are placed at right angles to its front edge.

(A) whose single set of strings runs parallel to the front edge of the instrument, the harpsichord's several sets of strings are
(B) with a single set of strings running parallel to the front edge of the instrument, the several sets of strings of the harpsichord are
(C) which has a single set of strings that runs parallel to the front edge of the instrument, in the case of the harpsichord, several sets of strings are
(D) which has a single set of strings that run parallel to the front edge of the instrument, the harpsichord has several sets of strings
(E) in which a single set of strings run parallel to the front edge of the instrument, the harpsichord's several sets of strings are

D

ASIDE: A virginal is a stringed instrument)

The opening phrase "Unlike the virginal..." sets up a COMPARISON.
So, after the modifying phrase "whose single set of strings runs parallel to the front edge of the instrument," the part IMMEDIATELY AFTER the comma should be the thing we are COMPARING with a virginal.
IMPORTANT: the two things we're comparing must be logically comparable. So, in this case, we are likely comparing the virginal with some other instrument.

A) Unlike the virginal . . . , the harpsichord's several sets of strings...
So, we're comparing an instrument (the virginal) with some instrument's set of strings.
This comparison makes no sense.
ELIMINATE A

B) Unlike the virginal . . . , the several sets of strings...
So, we're comparing an instrument (the virginal) with some instrument's set of strings.
This comparison makes no sense.
ELIMINATE B

C) Unlike the virginal . . . , in the case of the harpsichord...
Pure awfulness!
ELIMINATE C

D) Unlike the virginal . . . , the harpsichord...
Great! We're comparing two instruments. This comparison makes sense.
KEEP D

E) Unlike the virginal . . . , the harpsichord's several sets of strings...
So, we're comparing an instrument (the virginal) with some instrument's sets of strings.
This comparison makes no sense.
ELIMINATE E

Answer: C

Cheers,
Brent