885- 250- 199 "what 从句“

l_shasha

199.Personal trainers and fitness coaches are to the narcissistic 1980’s just like a private fencing master and dancing teacher was to an earlier time.
(A) just like a private fencing master and dancing teacher was
(B) as have been a private fencing master and dancing teacher
(C) what private fencing masters and dancing teachers were
(D) what private fencing masters and dancing teachers are
(E) just the same as private fencing masters and dancing teachers had been

answer is C, i know "were" is the must... but how to explain the "what sub-sentence" here?

thanks a lot!

ios

句形：A be to B what C be to D
A和B的关系正如C和D的关系。

l_shasha

thanks a lot!