单选题 If ______ to speak, he has no problem expressing himself.
A. asked B. asking C. ask D. to be asked

【正确答案】 A
【答案解析】[解析] 从句可以还原为If he is asked to speak，本句中省略了主语和谓语。根据分词逻辑主语和主句主语一致的原则，选项B被排除，选项C不合语法规则，选项D和主句时态不一致。