After the Arab state won independence

After the Arab state won independence
After the Arab states won independence,great emphasis was laid on expanding aducation,with girls as well boys ______ to go to school.
A.to be encouraged B.been encouraged C.being encouraged D.be encouraged
纠结在B和C之间!been的话,表示已经完成鼓励这个动作了,being表示正在被鼓励,这里到底用哪个啊?如何判断?
别给我表示伴随这种模糊的答复。请帮我解释一下如何判断是完成鼓励这种动作还是正在被鼓励！