A、Take a bus. B、On foot. C、Take a taxi. D、Take the subway. D地铁可以直达，而乘坐公交车需要换乘，出租车也不经过博物馆的，因此推知女士最有可能选择乘坐地铁。故D 为本题答案。

W: Well, I’m going to the National Museum of Art.
M: Sure. Hop in.
W: Uh, how long does it take to get there?
M: Well, that all depends on the traffic, but it shouldn’t take more than twenty minutes for the average taxi driver.
   And I’m not average. I have been driving down to an art, so we should be able to cruise through traffic and get there in less than twelve minutes.
W: Okay. Uh, sorry for asking, but do you have any idea how much the fare will be?
M: Oh, it shouldn’t be more than 18 dollars.., not including a... uh-hum... a tip of course.
W: Oh, and by the way, do you know what time the museum closes?
M: Well, I would guess around 6:00 o’clock. And it’s 4:30 now. Uh, this is your first time to the city, right?
W: Yeah. How did you know?
M: Well, (19)you can tell tourists from a mile away in this city because they walk down the street looking straight up at the skyscrapers.
W: Was it that obvious?
M: Well...
W: Oh, before I forget, can you recommend any good restaurants downtown that offer meals at a reasonable price?
M: Well, (20) the Mexican restaurant, La Fajita, is fantastic. It’s not as inexpensive as other places I know, but the environment is quite pleasing, and the portions are larger than most places I’ve been to.
W: Sounds great! How do I get there from the museum?
M: Well, you can catch the subway right outside the museum. There are buses that run that way, but you would have to transfer a couple of times. And there are taxis too, but they don’t run by the museum that often. (21) So I strongly recommend you to take the subway.
W: (21)Thanks for your advice.