求助一道语法

Congress is debating a bill requiring certain employers provide workers with unpaid leave so as to care for sick or newbom children.

(A)                            provide workers with unpaid leave so as to

(B)                             to provide workers with unpaid leave so as to

(C)                             provide workers with unpaid leave in order that they

(D)                             to provide workers with unpaid leave so that
            they can

(E)                              provide workers with unpaid leave and                    为什么能选D呢，不会指代不明吗，既可以employers. 又可以workers   谢谢！！！

  x

哦这样啊。谢谢~