What could be a possible explanation why tectonic plates do not all move in the same direction?
a. the magma moves the plates in the same direction, but slab pull makes them move away from one another.
b. the magma moves in the same circular path, but the plates bounce against each other and change direction.
c. the magma moves in “cells,” which circulate in different directions, moving the plates in more than one direction.
d. the magma’s movement in the mantle is highly erratic and causes the plates to move in circles.

The answer is letter C.

Plates move in different directions because the magma moves in “cells” which circulate in different directions. The intense heat of the Earth’s core causes molten rock in the mantle layer to move in a pattern called convection cell. When this occurs warm material rises, cools, and eventually sinks down, as this happens, it is again warmed and it rises again.

Plates help themselves move instead of just surfing along the mantle because of giant convection cells that change the structure of rocks through heat.