Here's why:
* Convection is the transfer of heat through the movement of fluids (liquids or gases). The heated fluid becomes less dense and rises, while cooler fluid sinks to take its place, creating a continuous cycle.
* Conduction is the transfer of heat through direct contact between molecules. This can occur in solids, liquids, and gases.
* Radiation is the transfer of heat through electromagnetic waves. This can occur in a vacuum and through all states of matter.
Therefore, convection is the only method of heat transfer that specifically requires the movement of fluids.
