Answer :
The correct option is c) conduction and convection. The evacuated space in a thermos bottle minimizes heat transfer by conduction and convection, and reflective surfaces further reduce heat transfer by radiation.
The space between the inner walls of a thermos bottle is evacuated to minimize heat transfer by conduction and convection. A vacuum is an effective insulator because it significantly reduces the ability of heat to be transferred via the molecular collisions that characterize conduction and the mass movement that defines convection. However, heat transfer by radiation can still occur, which is why thermos bottles often have reflective surfaces to minimize this effect. The correct option is c) conduction and convection.
