哪位高手能讲讲这道题好吗？谢了！

Netherlanders

Scientists claim that the discovery of the first authenticated mammal bones in amber could provide important clues of determining, in addition to how, when mammals colonized the islands of the West Indies.

A.    of determining, in addition to how, when mammals colonized the islands of the West Indies
B.    in the determination of how and when the islands of the West Indies were colonized by mammals
C.    to determine how mammals colonized the islands of the West Indies and when they did
D.    for determining when the islands of the West Indies were colonized by mammals and how they were
E.    for determining how and when mammals colonized the islands of the West Indies

avenue5th

Scientists claim that the discovery of the first authenticated mammal bones in amber could provide important clues of determining, in addition to how, when mammals colonized the islands of the West Indies.

A.    of determining, in addition to how, when mammals colonized the islands of the West Indies
B.    in the determination of how and when the islands of the West Indies were colonized by mammals
C.    to determine how mammals colonized the islands of the West Indies and when they did
D.    for determining when the islands of the West Indies were colonized by mammals and how they were
E.    for determining how and when mammals colonized the islands of the West Indies

答案选E吧？
A太啰嗦了，in addition to how, when 什么的，没这说法啊，干掉
B形势就觉得不怎么爽，干掉
对比CDE，感觉to determine和for determining差不多，先放着，后面是说提供线索用来知道when和how     mammals colonized the islands of the West Indies 的，感觉WHEN和HOW的关系是并列，且DE中后面出现了when they did和how they were，还要让人想they指代什么，所以E的答案更清晰，语意上也比较流畅

torresAing

C为啥不对啊、、、

Sunfisher006

搞清楚to do 和for doing的区别。 for doing在一般情况表目的是累赘的 但是to do 在c中 的主语指代错误