A、Pounding. B、Pulse beat. C、Gradually. D、Suddenly. D题目问的是男士如何描述发病时的情况，男士用pounding和pulse beat来形容疼痛，用out of the blue来形容“突然，毫无准备”，

M: I’m asked to pick up the guest speaker Bob Russel at the airport this afternoon, do you know what he looks like?
W: Well, he’s in his sixties, he stands out, he’s bald, tall and thin and has a beard.
Q: What do we conclude from the woman’s remarks about Bob Russel?

W: Could you give me a description of what it feels like? You know, aching, burning, or whatever you’d describe it?
M: It is more like pounding, like you feel each pulse beat.
W: How do they begin, gradual or all of a sudden?
M: Pretty much out of the blue.
Q: How does the man describe the onset of the pain?