These four subsystems are called "spheres." Specifically, they are the "lithosphere" (land), "hydrosphere" (water), "biosphere" (living things), and "atmosphere" (air). Each of these four spheres can be further divided into sub-spheres
Oceanic crust is more dense which makes it subduct and continental crust is less dense which makes it override the oceanic crust during subduction
Albedo feedback is a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of a planet. ... However, if warm temperatures decrease the ice cover and the area is replaced by water or land the albedo would decrease.
B. Their remote location has kept out invaders.