How Does the Theory of Island Biogeography Apply to Habitats

How does the theory of island biogeography apply to habitats not on islands?

A) It doesn't. It only works on islands.
B) On land, the relationship is reversed. Smaller areas of land tend to have relatively more species.
C) Small isolated areas of habitat on land, surrounded by unsuitable habitat, are like "islands" so bigger areas have more species.
D) It's similar but on land, species on "islands" of habitat are much less likely to go extinct because it's easier to migrate.
E) No one has tried to apply it to land, but it seems like it would work the same way.