The correct response is: Both waves cause earthquakes.
P-waves (primary waves) and S-waves (secondary waves) are both generated during an earthquake and propagate through the Earth. However, only P-waves move the ground in the direction they travel, while S-waves move the ground perpendicular to their direction of travel. Therefore, the other statements do not accurately describe both types of seismic waves.
Additionally, seismic waves do not occur in the ocean specifically; they occur in the Earth's crust during earthquakes.