\\\\(\ extbf{Step 1}\\\\): There are three modes of transmission of heat. They are Conduction, convection and radiation. Conduction: In this mode of transmission. heat dissipates from one place to another by molecular vibration. It is relevant to solid only. Conduction needs a medium to transfer heat. Convection: Heat is transferred from one place to another by the transfer of molecules. It happens only in liquids or gases. It also needs a medium to transfer heat. Radiation: It transfers heat in the form of electromagnetic waves. It can heat any form of material. It doesn't need any medium for the transfer of heat. \\\\(\ extbf{Step 2}\\\\): We know that radiation travels with the speed of light. So, the rate of heat transfer is maximum in radiation in the form of electromagnetic radiation. Thus option C is correct.