Based on the theory of island biogeography, which of the following islands would most likely have the highest number of species living on it?
a. An island 30 hectares in size that is 30 kilometers off the coast of the mainland
b. An island 30 hectares in size that is 10 kilometers off the coast of the mainland
c. An island 10 hectares in size that is 30 kilometers off the coast of the mainland
d. An island 10 hectares in size that is 10 kilometers off the coast of the mainland