The correct answer is convection because the campfire warms the air around the person.
Convection refers to the transfer of mass motion of a fluid like water or air when the heated fluid is made to be carried away from the heat source, that is, carrying energy with it. Convection takes place when particles with an ample of heat energy in a gas or liquid move and occupy the place of constituents with less heat energy.
Heat energy is conducted from hot places to cooler places by the process of convection.