听力原文：M: You know, I feel really dumb. Um, there's so much that I don't know and so muc

h to read that I can't process all the information available. Do you feel the same way？

W: I know what you mean. There's so much to find out about in so many different ways nowadays. We have television, we have radio, and we have all sorts of magazines.

M: Even in your own field, you know, you'd have to read twenty or thirty magazines a month in order to keep up.

W: Just to know what's happening.

M: Yeah. That's right.

W: You know, now, because of communication systems, uh, our sphere of interest is the whole world, whereas before, our sphere of interest was just our country or our area.

M: Yeah, yeah, that's right.

W: I think we realize now that we should know things. And therefore, we are pressed to know these things.

M: Yes, we're..., whereas before people didn't understand that...

W: And as an educated adult you also have to keep up with certain international events and affairs, or you cannot really be a responsible person.

M: Yeah, you know you're responsible for making decisions about not only your own life, but many other things and you have to be informed to be able to do that.

W: You have to learn to pick and choose information too.

Why does the man feel dumb？

A．He can't process all the information available.

B．There is so much he doesn't know.

C．There is so much he hasn't read.

D．All of the above.