单选题 A responsible therapist gives sound advice to his clients to help ______ enjoy a higher quality of life.

【正确答案】 C

【答案解析】[解析] 语法：代词
1．本题考查代词的格，使役动词help后一定要接宾语，因此C为正确选项。
2．应留意空格后的enjoy。不能选择主格代词they。