The correct answer is D) convection current.
Convection currents are the cycle of warm air rising and cool air sinking that occurs in Earth's atmosphere (as well as in other fluids) as a result of temperature differences. When a fluid (such as air) is heated, it expands and becomes less dense, causing it to rise. When the warmer fluid cools, it contracts and becomes denser, causing it to sink. This cycle of rising and sinking creates a circular flow known as a convection current.