There Is an Island in the Middle of a Large

Multiple Choice

There is an island in the middle of a large river that houses a large population of ants.Damming of the river causes the island to flood and only the highest points of the island are now above water.The ants cannot swim,so are now in multiple isolated populations.Which of the following best describes this event?

A) isolation by dispersal
B) isolation by vicariance
C) a form of sympatric speciation
D) only a rare development of polyploidy could lead to speciation in this case.
E) speciation will not occur in this case because of gene flow