I think they are dating. They _____ a lot of each other recently

I think they are dating. They _____ a lot of each other recently.
A、had seen
B、had been seeing
C、have seen
D、have been seeing
【正确答案】：D
【题目解析】：D现在完成进行时翻译：我想他们正在约会，他们最近一直在见面。从过去到现在一直发生的动作，并还在继续，用现在完成进行时。选项D是正确的。