The Major Volcanoes on Mars Have Formed

The major volcanoes on Mars have formed

A) in mountain belts where the planet's surface is being stressed as it is bent and subducted back into the mantle.
B) where shrinkage of the crust during cooling early in the planet's history has wrinkled the surface.
C) on long, interconnected ridges where magma, rising from the mantle, is pushing the crust apart.
D) over individual stationary hot spots in the underlying molten mantle.