Earth's Internal Layers Were Discovered by Studying the Propagation of P-

Earth's internal layers were discovered by studying the propagation of P- and S- waves through Earth's interior. In comparison to S-waves, the movement of P-waves is

A) fast, compressing and expanding the rock as they move through it.
B) fast, vibrating the rock particles up and down and side-to-side.
C) slower and can travel through solid granite, magma, water or air;
D) slower and can travel only through solids, not liquids.