Concept:Heat transfer through a solid metal like an iron bar is called conduction.Explanation:Conduction is the transfer of heat through a material without the material itself moving.Iron is a good conductor of heat, so heat travels along the bar from the hot end to the cold end.Convection involves liquids and gases, not a solid iron bar.Radiation does not need a medium and is not the main way heat moves along a solid bar.Absorption is not a process of heat transfer.Answer:B. conduction.