How do earthquake (seismic) waves allow scientists to determine the composition of Earth layers? Question 20 options:

A The waves are blocked, showing the layers are solids.

B The waves are shortened, showing the layers are made of the same material.

C The waves are lengthened, showing that the mantle is made of water and salt.

D The waves are traveling at different speeds, some bend or refract, the shadow zone doesn't record any s waves, showing the layers have different compositions.