gwd-8-Q31:GWD-2-12 不明白 望解答 nn

GWD-8-Q29:

Because of a similarity to dance, synchronized swimming—exhibition swimming in which the movements of one or more swimmers synchronize to a musical accompaniment—is sometimes called water ballet, especially in theatrical situations.

A.      of one or more swimmers synchronize to

B.       of one swimmer or more is synchronized with

C.      of one or more swimmers are synchronized with

D.      by one swimmer or more is synchronized to

E.       by one or more swimmers synchronize to

我选的是b 答案给的是d   synchronize是什么用法呢？？？  of 和by是怎么区分的呢？？ 谢谢啦 NN