The correct answer is A. Earth’s crust.
Earthquakes are caused by the sudden release of energy in the Earth’s crust. This energy can be released when tectonic plates move, when magma rises to the surface, or when there is a sudden change in pressure in the Earth’s crust.
The Earth’s crust is made up of tectonic plates. These plates are constantly moving, and they can grind against each other or collide. When this happens, the plates can stick together, and the energy builds up. Eventually, the energy is released, and the plates move past each other. This movement can cause the Earth’s surface to shake, and it can also cause damage to buildings and infrastructure.
Magma is molten rock that rises to the surface from the Earth’s mantle. When magma rises to the surface, it can cause the Earth’s crust to move. This movement can also cause earthquakes.
A sudden change in pressure in the Earth’s crust can also cause earthquakes. This can happen when there is a large amount of water that suddenly moves underground. The water can cause the Earth’s crust to move, and this movement can cause an earthquake.
The other options are incorrect because they are not the main cause of earthquakes. Deep seas, peak mountains, and forests do not have a significant impact on the Earth’s crust, and they do not cause earthquakes.