A、On the first floor. B、On the second floor. C、On the third floor. D、On the fourth floor. AWhich floor is the flat on?

W: Hello, is that 3422897
M: Yes, it is.
W: I’m inquiring about the flat which was advertised in the evening paper?
M: Oh yes?
W: I wonder if you could tell me how much the rent is a month, please?
M: It’s $130.
W: I see. Is it near the city centre?
M: Yes, it’s only about a kilometer away.
W: Which floor is it on?
M: On the first floor.
W: I see. Would it be possible for me to see it tomorrow, say 6 o’clock?
M: Yes, certainly.