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

Earth's internal layers were discovered by studying the movement 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.