13.
Your Answer is
Correct Answer is D
Explanation
Item D: The brothers' musical repertoire (playing repertoire) is compared with their instruments, correct.
The underlined part is the subject-predicate part of the sentence, so A/B is wrong,
Item A: while is a conjunction, making it a subordinate clause, and the sentence lacks a main clause, so it is wrong.
Item B: The with prepositional phrase cannot be the subject, so it is wrong.
Item C: having cannot be compared with their instruments later, so the meaning of the sentence is wrong.