单选题 She started to learn English when she was very young, ______ contributes to her success in her career.

【正确答案】 D
【答案解析】[解析] which引导非限制性定语从句,指主句的全部内容。如:The sun heats the earth, which is very important to us. (太阳给地球带来热量,这对于我们是很重要的。)