A、A safety briefing. B、A health certificate. C、His birth certificate. D、A backwards jump. B对话中女士问男士蹦极有没有年龄限制，因为她的父亲马上就50岁了，男士回答说

M: Hello. Grayson’s Adventure Days. How can I help you?
W: Oh, good morning. I want to book an activity day as a birthday present for my father, so could you give me an idea of the sorts of things you organise?
M: What a great present! Do you want the activity to take place in a particular location?
W: No, anywhere in the country would be OK.
M: Right. Well, how about bungee jumping? That’s our most popular activity.
W: Uh-huh?
M: After a safety briefing, you’re securely fastened to the correct bungee rope for your weight. Then the crane takes you up to a height of 50 metres in a cage, and you jump from it.
W: You make it sound so easy!
M: In fact, some people change their minds at the last moment. But for the really brave, you can also book our special, which is one normal bungee jump and then a backwards one. It’s quite an experience!
W: I can imagine! Is it available every day?
M: We do bungee jumping all year round, on over 120 days, and in various locations,[13]but you should try to book about four weeks in advance, if possible, as it’s very popular.
W: OK. And are there any age restrictions? It’ll be my father’s fiftieth birthday, so I hope he isn’t too old.
M: No, he certainly isn’t too old, but we’ll require a certificate from a doctor, to confirm that he’s in good health.
W: Oh, he’s very fit, so that won’t be a problem. How much is it?
M:[15]It costs ￡57 per person for the standard jump, and ￡97 for the special.
W: OK, I’ll get back to you in the next few days. Thanks very much for your help.
M: No problem. Bye.
W: Bye.
12. Why does the woman want to book an activity day?
13. What should the woman do if she books bungee jumping?
14. What is required for the woman’s father to make a bungee jump?
15. How much cheaper is it to book the standard jump than the special one?