M: I can't stand this heat. I can't get my attention to studying for the midterm exam. I guess I'll have to go to the library this afternoon. ,F: I don't blame you. This dormitory doesn't have air conditioning. I can't study, either. My roommate and I are thinking about moving out to the other dorm, or an apartment that has air conditioning. ,M: Oh, I thought about moving to. But if I want to live in an apartment, I have to pay a lot of money for electricity. Do you know an air conditioner is cheaper today than it was 10 years ago? On the other hand, electricity is a lot more expensive today. ,F: I didn't know that. How much do we have to pay for the electricity? 5 years ago, it was possible to run an air conditioner 24 hours a day for mere $20 a month. Today, the same air conditioner in the same house cost more than $40 a month.
(A) M: Excuse me, could you repeat the question? (B) M: That means $35 will cost to run an air conditioner 24 hours a day for 2 months 5 years ago. (C) M: Today, as five years ago, running an air conditioners 24 hours a day cost $20 for 2 months. (D) M: Electricity is cheaper today. 5 years ago, running an air conditioners 24 hours a day cost $40 for 2 months.
A