Why Are Islands and Island-Like Habitats Considered Appropriate Models for Illustrating

Why are islands and island-like habitats considered appropriate models for illustrating the species-area relationship?

A) Islands provide a defined and isolated area that can more easily be studied.
B) Species diversity on islands tends to be high due to increased concentrations in smaller spaces.
C) The isolated nature of island geography contributes to higher incidences of extinction than mainland areas do.
D) Islands can be colonized only by immigration, which is the most important factor in the species-area relationship.
E) The species-area relationship holds true only in habitats that are completely isolated from other areas.