听力原文：M: So you're visiting San Francisco？
W: Yes, I just got here yesterday. And you？
M: I' m a native.
W: Oh, really？ Everyone else I've met so far has been a tourist like us. I was beginning to think that there were no natives.
M: Well. San Francisco has a lot of different ethnic groups so you might think you' re seeing a lot of foreigners. But actually, the city has a population of about 700 000.
W: What are the different ethnic groups？
M: Web, after whites, the largest one is blacks.
W: I thought it was Chinese.
M: It' s true that San Francisco has the largest Chinese community outside of Asia. But there are many more blacks here than Chinese.
W: That' s interesting. Don' t most of the Chinese people live in China-town？
M: Well, no, they live all over the city, but China-town is definitely the center of Chinese culture here. That' s where you' ll find the best Chinese restaurants, bookstores, art, theaters, things like that.
W: What about the Japanese？ Doesn' t San Francisco have a large Japanese population too？
M: No, actually there are only about 12 000 Japanese people here, but we do have an area called "Japan-town" that has Japanese restaurants and bookstores.
W: You seem to know a lot about this city.
M: Well, most San Franciscans think their city is pretty special. We like to talk about it. Besides, I teach ethnic history at the university here.
W: No wonder you know so much!
What is the largest ethnic group in San Francisco？

A. The blacks.
B. The whites.
C. The Chinese.
D. The Japanese.