单选题 He couldn't say what it was ______ bothered him.
A. it B. which C. that D. as

【正确答案】 C
【答案解析】[解析] 这是一种隐含强调句，不仔细分析很容易弄错。say的宾语从句是what bothered him，强调的部分是从句的主语what。