问题详情

Which of the following prepositional phrases is an adverbial of concession？(2012)

A．They used the box for keeping treasures.

B．I stepped aside for her to get in first.

C．For all that he seems to dislike me, I still like him.

D．The parents bought a birthday cake for their son.

请帮忙给出正确答案和分析，谢谢！