The lithosphere floats on the asthenosphere like glass on clay. when the clay moves, the glass moves. the movement of the lithosphere is

seafloor spreading
plate tectonics
volcanic activity
earthquakes

Option (2)

Explanation:

The lithosphere is the region that is comprised of the crust and a portion of the upper mantle. It is a region where all the essential minerals are present and also the living beings exist. It is made of rocks of variable composition. The lithosphere is made up of numerous large and small plates that are constantly in motion over the less dense asthenosphere layer, due to the convection current that generates in the mantle. This convection current initiates because of the heat radiated from the core of the earth.

Thus, this movement of the lithosphere is known as the plate tectonic movement.

Hence, the most appropriate answer is option (2).