20:

New genetic evidence—together with recent studies of elephants’ skeletons, tusks, and other anatomical features—provide compelling support for classifying
            Africa’s forest elephants and its savanna elephants as separate species.

A.      provide compelling support for classifying

B.       provide compelling support for the classification of

C.      provides compelling support to the classification of

D.      provides compelling support for classifying

E.       provides compelling support to classify

答案选D，而我觉得是E。

请牛牛们解答下~~~万分感激~~

哦，这样子啊~~好像有点明白了，谢谢啦~~