A、They are sisters. B、They are twins. C、They are mother and daughter. D、They are identical twins. D

M: We continue with the World of Investigation. Susan, an identical twin, has agreed to contribute to our investigations. I must apologize for the fact that Susan’s twin cannot be here tonight. And I’d like to tell you, Susan, how sorry we are. You and your sister are very close, aren’t you?
W: Of course we are.
M: Interesting! You said "of course". Don’t you think there are quite a few sisters who aren’t close?
W: Brenda and I aren’t just sisters. We’re identical twins.
M: I take your point. How identical are you, in fact?
W: Both blonde, with brown eyes. Same height, same weight, same size. Even shoes.
M: As you’re the same in size, have you always dressed alike?
W: Oh yes. I’m told it started when we were babies. Mum made a feature of her twins. And then we got into the habit of buying two of everything.
M: And you’ve never minded having a double identity? I mean...another person exactly like you?
W: Brenda isn’t exactly like me. We may look identical, but...I remember our boyfriends couldn’t tell us apart.
M: Didn’t that cause problems?
W: For them, perhaps. Not for us. We couldn’t stop laughing.
M: I think you said you and Brenda weren’t exactly alike? Just what did you mean by that?
W: Brenda has a well-fed happy husband and four healthy children. When she was washing up, I was learning to type. When she was knitting, I was writing articles for the school newspaper. When she was having her second child, I was in Panama, doing my first job Dolphine Credit. See what I mean?
M: And haven’t you got a healthy husband and happy children?
W: You must be joking. There’s never been the time...or the inclination.
M: Susan, you’ve made some very interesting points. I gather that you don’t feel that behavior is purely genetic... that there might be some element of environment or choice or even perhaps...
W: Shall I conclude? Brenda and I are identical twins in appearance...in appearance, that is...but it’s a fact that life has presented us with different opportunities, so we’ve led very different lives.
19. Where does the interview most probably take place?
20. What’s the relationship between Susan and Brenda?
21. In what ways are Susan and Brenda identical?
22. Which of the following statements is correct?