请教新prep-1-217

Not one of the potential investors is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were not to be concluded.

A. is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were

B. is expected to make an offer for buying First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal was

C. is expected to make an offer to buy First Interstate Bank until a merger agreement be signed by them with a provision for penalties if the deal were

D. are expected to make an offer for buying First Interstate Bank until it signs a merger agreement with a provision for penalties included if the deal was

E. are expected to be making an offer to buy First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal were

请问A中the deal 用were可以吗？不是单数吗？

A. is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were

B. is expected to make an offer for buying First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal was -

C. is expected to make an offer to buy First Interstate Bank until a merger agreement be signed by them
            with a provision for penalties if the deal were

D. are expected to make an offer for buying First Interstate Bank until it signs a merger agreement with a provision for penalties included if the deal was
            

E. are expected to
            be making an offer to buy First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal were 

B中make XXX to do sth. for buying 不符合idiom. they 指代不清晰

C中be signed句法不对，因为后面的虚拟是一种省略的用法，没有主句，这里的a merger agreement is signed是一个独立的句子,而不是if the deal were XXX 的主句

D not one of XXX 应该和one of XXX的用法一样，都是单数，are expected就不正确， for buying不正确。it指代不清，如果按照就近原则的话，应该是修饰bank，不正确。with a provision for penalties included，有些冗余。

E are expected就不正确， they指代不清