单选题 Speaker A: I"m getting pretty bored. We should do something despite the rain.
Speaker B: ______ What do you have in mind?

【正确答案】 C

【答案解析】[解析] “I back you up”意思为“我支持你”；“Who cares?”意思为“谁在乎?”；“I"m with you”意思为“我同意”。甲方提议做点什么，乙方表示同意，并问对方有何想法。A项也勉强讲得通。