The method of transmission of heat is

The method of transmission of heat includes conduction, convection, and radiation, covering all the given options. Conduction is the transfer of heat through direct contact between molecules, typically occurring in solids. An example is a metal rod heating up when one end is placed in a flame. Convection is the transfer of heat through the movement of fluids, such as liquids and gases. This process can be observed when warm air rises and cool air descends, creating convection currents. Radiation is the transfer of heat through electromagnetic waves, which can occur even through a vacuum. The heat we feel from the sun is due to radiation. Each of these methods operates under different principles and in different mediums, but together, they encompass all the ways heat can be transmitted. Therefore, the correct answer is [D] All of the above.