HKD1710
The piano, one of the most commonly played instruments, produces deep and complex sounds,
every sound a small component of its acoustic production.
(a) every sound a small component of its
(b) all the sounds a small component of their
(c) all the sounds a small component of its
(d) each sound a small component of their
(e) every sound a small component of their
Source : Grockit
Dear HKD1710,
I'm happy to help, my friend.

I am not particularly impressed with this SC question. It's quite formulaic in its splits, and not particularly GMAT-like.
Split #1: the final pronoun clearly refers to "
the piano," and so should be the singular "
its," not the plural "
their." Choices
(B) &
(D) &
(E) can be eliminated on this account.
Split #2: The phrase "
a small component" is singular in all five choices, so the element identified with this also must be singular. We need "
every sound" or "
each sound," not "
all the sounds." Because of this, we can eliminate choices
(B) &
(C).
After two easy splits on sing/pl, the question is exhausted. We are left only with
(A), the OA.
What most strikes me about the question is that the structure in the prompt, an
absolute phrase, is very sophisticated----it's a structure that can be particularly confusing to non-native speakers. A high quality SC practice question would have tested putting that information in an absolute phrase vs. some other form, thus exploring the student's understanding of absolute phrases. To have a structure this sophisticated and to create a question that tinkers only with simple singular/plural splits falls astonishingly short of the standards for SC held by the GMAT. As someone who writes GMAT SC practice questions, I would give this question a grade of a
D+. It has so much potential, and the question writer chose to do the absolute minimum with it.
Here's a much higher quality SC practice question:
https://gmat.magoosh.com/questions/3218When you submit your answer, the page that comes up will have a full video explanation of the question.
Does all this make sense?
Mike