- Hey, what are you doing in that room?
-___________________

选择一项：
A. Fine. Thank you.
B. I am preparing for the test next week.
C. Nothing in particular.

B. I am preparing for 解析：本题考核“问询与解释”的交际用语。What are you doing? 意思是“你在那房间做什么呢？”如果没有做什么特别的事情，答者可以说Nothing in particular. 意思是“没什么”。但如果在做什么事，最好明确回答。因此，选项“I am preparing for the test next week.”比较符合题意。the test next week.