求助一道非谓语动词的选择题

题目

求助一道非谓语动词的选择题
The research is so designed that once _____ nothing can be done to change it .
A.begins B .having begun C.beginning D.begun
我认为应该选C,因为从“研究开始”这种说法来看research和begin应该是主动关系阿,而且在一个辞典上还有一个例句是“The work on the railway project will begin in 2008.”我觉得这里的work同本题的research一样,对于begin用主动形式

答案

应该是D
The research is so designed that once (it is) begun,nothing can be done to change it.
这里的begun是被动语态做形容词