The Theory of Island Biogeography Says That the Number of Species

The theory of island biogeography says that the number of species on an island of a given size will stay fairly constant over time. How did the Simberloffs test this using mangrove islands in Florida, and was the theory supported?

A) They counted all the insects on a group of islands over time and the numbers didn't change so the theory was supported.
B) They removed all the insects on a group of islands and then monitored how many came back. Before and after numbers were similar, so the theory was supported.
C) They removed all the living species on a group of islands over time and monitored how many came back. Before and after numbers were similar, so the theory was supported.
D) They removed all the insects on a group of islands and then monitored how many came back. Very few came back, so the theory was not supported.
E) They physically isolated a group of islands and then monitored all the species over time. The numbers changed quite dramatically so the theory was not supported.