Question

what is the main cause of an earthquake?
force of gravity
the shaking of the ground
stress caused by plate movement
waves that ripple from the epicenter

Explanation:

Earthquakes occur mainly due to the stress generated when tectonic plates move and interact with each other. Gravity is not the main cause. The shaking of the ground is an effect of an earthquake, not the cause. The waves from the epicenter are also a result of the initial stress - release due to plate movement.

Answer:

C. stress caused by plate movement