—Do you mind if I smoke here?

—_____．I’ve got a bit of cold these days．

A．I’m afraid I do

B．Of course not

C．No trouble at all

D．Yes, just go ahead

下述对于引物酶的描述恰当的为

A．引物酶也称DnaB蛋白

B．属依赖RNA的RNA聚合酶

C．具有催化引发体形成的功能

D．能催化3',5'-磷酸二酯键生成