Which of the following is not a mode of heat transfer?
There are three modes of heat transfer: conduction, convection and radiation. Any energy exchange between bodies occurs through one of these modes or a combination of them. Conduction is the transfer of heat by physical contact. Convection uses the movement of fluids to transfer heat. Heat radiation is the transfer of heat energy through electromagnetic waves. Radiation doesn't require any medium.
Reflection means bouncing of light wave when it strikes an object. It is not a mode of heat transfer.