Why are most volcanoes found where the Earth's crust has been broken?

A. Magma is hotter along these crusts and can melt any rocks above it.
B. There are more seismic waves that cause magma to rise to the surface.
C. The broken crust creates high pressure that causes magma to rise.
D. The broken areas of the crust provide an opening where magma can travel to the surface of Earth.