What statement is true of convection?

Convection is the process of heat transfer through the movement of fluids (liquids or gases) caused by differences in temperature and density. As a fluid is heated, it becomes less dense and rises, while cooler, denser fluid sinks, creating a circulation pattern. This mechanism is responsible for various natural phenomena, such as ocean currents and weather patterns. Convection plays a crucial role in many heating and cooling systems, such as radiators and air conditioning units.