— No one can answer the question _______ we can complete the task in time, do you know?

— Yes, and this is because we don’t know the way _______ the scientist used last time．

A．whether; which

B．if; which

C．whether; in which

D．if; in which

领取生育津贴期间社保怎么处理？单位必须为我缴纳社会保险吗？