一道og语法，忘指教：）

moonstone

67. 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
key:d
可我觉得b没什么错呀，在这里为什么不能用so as to?

自尊宝

so as to 要求前后的主语一致