A、Because David liked animal. B、Because it was David’s birthday. C、Because she liked pets. D、Because David had asked her for one

W: Hello, Tom.
M: Hello, Mother.
W: I want to buy David a pet for his birthday.
M: Yes, I know.
W: What shall I give him?
M: Why don’t you buy him a dog? He likes dogs because they are friendly.
W: But he’ s already got a dog.
M: Yes, that’s true. What about buying a cat? Cats eat mice.
W: But he’s got a pet mouse. Prod lie can’t take a eat for a walk, can he? Anyway, I want to buy him something unusual.
M: You could buy him a rabbit.
W: A rabbit? What can he do with a rabbit?
M: Well, rabbits are very pretty. He can feed it, and play with it. He can build a house for it. He likes building things.
W: I don’t think that’s a very good idea. Rabbits aren’t interesting. What about a snake?
M: A snake?
W: Lots of people have snakes. They me very clean and easy to look after. And they’re very unusual pets. David likes snakes.
M: I don’ t. No, don’ t buy a make. I don’ t want to open my bedroom door and find a snake.
W: What do you suggest then?
M: Why don’ t you buy a bird? They’ve got some parrots at the market. They’ve very pretty and they can talk, too. Parrots are unusual.
W: I don’t like birds. They everywhere, and they make a lot of noise and a lot of mess.
M: Oh, I really don’ t know what else I can suggest.
W: I want to buy something unusual.