When I finally got up to leave, we both knew that a real friendship ________ between us

When I finally got up to leave, we both knew that a real friendship ________ between us

A.have formed

B.will form

C.is to form

D.was to form

答案及解析： D

解析：

主句中的谓语knew用的过去式，从句也要用相应的过去时态，排除A、B、C。只有D项是过去时态，故选D。