Which of the following is not a method of transferring heat?
a. convection
c. reduction
b. radiation
d. conduction

The answer is Reduction. All three methods (convection, radiation, and conduction) are all ways of transferring heat. Convection is the transfer of heat by means of a medium such as air. Conduction is the transfer of heat from the contact of two surfaces at different temperatures. Radiation is the transfer of heat via electromagnetic waves.

Reduction is a chemical reaction that involves the gain of electrons. It is the opposite of oxidation which involves the loss of electrons.