Many Times Species Are Composed of Networks of Distinct Populations

Many times species are composed of networks of distinct populations called metapopulations.Metapopulations occur in areas where

A) a population in better habitats continually sends out dispersers to bolster populations in poorer habitats.
B) a population in poor habitat continually sends out dispersers to bolster populations in better habitats.
C) a population in better habitats does not send out colonizers into poorer habitats.
D) suitable habitat is patchily distributed and separated by areas of unsuitable habitat.