A room is heated by means of a charcoal fire, an occupants of the room standing away from the fire is warmed mainly by
Convection
Radiation
Conduction
Reflection
Correct answer is B
Radiation refers to the transmission of energy as electromagnetic radiation from its emission at a heated surface to its absorption on another surface, a process requiring no medium to convey the energy.
Conduction is the transferring of heat by direct contact.
Convection is transferring heat through the motions of fluids (gases and liquids).