A、  B、  C、  C题干是叙述句的情况，只要选择与其意思相符的选项即可。题干说如果能够租一辆车可方便多了，(C)项的回答“是的，但是公交车更便宜”符合题意。(A)项如果改为Yes，I think it is．就是正确选项

You have the day off tomorrow, don’t you?
(A) He already planned it.
(B) Yes, I’m going to see family.
(C) They’re meeting during the day.

It’s more convenient if we rent a car.
(A) Yes, I think they are.
(B) No, I just bought it new.
(C) Yes, but a bus would be cheaper.