Seismometers measure

a. body and surface waves
b. ocean waves
c. sound waves
d. electromagnetic waves

b, ocean waves

Explanation:

seismometer are used by seismologists to measure and record seismic waves, by studying seismic waves,geologists can map the interior of the earth, and measure and locate earthquakes and others ground motions,the term seismograph is usually interchangeable but seismometer seems to be a more common usage

velocity and height

i think that the best answer would be c.

tell me if im wrong : )