GMAT Reading Comprehension (RC) | Many aspects of coral reefs remain puzzling to scientists.

1 - A
In the portion "Although Darwin's view of the transformation is considered partially correct, some scientists feel that the creation of reef formations has more to do with the rise in sea level that occurred at the end of the last Ice Age than with a gradual submergence of the volcanic islands to which fringing reefs were originally attached. However, recent drillings at one atoll have revealed a substantial underlayer of volcanic rock, which suggests that Darwin's explanation may be
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