Evidence of Earth’s plate tectonic activity is most obvious after an earthquake. Which explanation best describes this plate tectonic movement? A: Earth’s plates stress one another. However, when an earthquake occurs, plate movement is due to an unbalanced force on the plates.

B: Earth’s plates are moving fast. However, the force of friction slows their movement.

C: The force of gravity causes the floating plates to move up and down. The plate movement sometimes results in earthquakes.

D: Earth’s plates continually place stress on one another. However, the force is balanced during an earthquake.