2) seismologists studying seismic waves and their behavior as they pass through parts of the earth are able to determine: a) densities of rock material b) thickness of parts of the earth (crust, mantle, core) c) location of earthquake foci d) all of the above apply e) a and b only apply

d) all of the above apply

Explanation:

Seismologists -

are the people who studies and collect data on the vibrations which occur in the interior of the Earth's surface , which can lead to tsunamis and earthquakes .

They go through the composition , structure and the Earth's process .

They study the seismic waves , which helps to determine , the density of the rock , location of the foci of the Earthquake , thickness of the layers , core , mantle and crust .