在一句话里，是否they和their必须指代同一对象？-->新东方语法课上讲的，但在实际操作中，如og90，主语的their 和从句的they 指代的不是同一对象，不知道该怎么对待这一规则
Since 1986, when the Department of Labor began to allow investment officers’ fees to be based on how the funds they manage perform, several corporations began paying their investment advisers a small basic fee, with a contract promising higher fees if the managers perform well.
(A) investment officers’ fees to be based on how the funds they manage perform, several corporations began
(B) investment officers’ fees to be based on the performance of the funds they manage, several corporations began
(C) that fees of investment officers be based on how the funds they manage perform, several corporations have begun
(D) fees of investment officers to be based on the performance of the funds they manage, several corporations have begun（D）
(E) that investment officers’ fees be based on the performance of the funds they manage, several corporations began | 
