Sentence Correction

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

Any thoughts???