1. Once the economic and social usefulness of the motor car was demonstrated and with its superiority to the horse being proved, much of the early hostility to it in rural regions disappeared.

(A) and with its superiority to the horse being

(B) and its superiority over the horse had been

(C) and its superiority to the horse

(D) its superiority over the horse（C）

(E) with its superiority to the horse having been

为什么答案是C不是B?

Thanks

1. had been与前面的时态was不一致.

2. C，因为平行，was proved里面的was被省略了.

B的时态是不对

可是固定用法中并没有 its superiority to the horse

只有its superiority over the horse