Answer:
the cycle of heated rock or metal rising, and cooling rock or metal falling.
Explanation:
Convection currents refer to the movement of a fluid, such as air or liquid, caused by differences in temperature and density within the fluid. In the context of the Earth, convection currents in the mantle are responsible for the movement of tectonic plates, which leads to phenomena like earthquakes and volcanic eruptions. So, the correct definition is: "the cycle of heated rock or metal rising, and cooling rock or metal falling.