The most widely accepted cause of plate movement is mantle convection.
Mantle convection is the process by which hot, molten rock from the Earth’s mantle rises toward the surface, cools, and then sinks back down. This movement creates currents that can push and pull the tectonic plates that make up the Earth's lithosphere, leading to various geological phenomena, including earthquakes.
The other options you mentioned—ocean waves and hot spots—are related to geological and oceanographic phenomena but do not directly drive the movement of tectonic plates. Ocean waves are primarily caused by wind and do not influence tectonic plate movement. Hot spots are stationary plumes of heat from the mantle that can create volcanic activity but do not explain the overall movement of plates.