单选题 What I say or what I think ______ no business of yours.
A. is B. are C. has D. have

【正确答案】 A
【答案解析】[解析] what I say和what I think都是名词性从句(即相当于一个名词单数)，凡名词性从句作主语时，谓语动词一律用第三人称单数。