___________I been there,I could have explained it.

___________I been there,I could have explained it.
A、Would
B、Have
C、Should
D、Had
【正确答案】：D
【题目解析】：could have done sth 本可以做某事，表示对过去的虚拟，因此从句要使用过去完成时，因此选D