I’m pretty positive that it’s A. Conduction. Just refer to the definition of it.
Answer:
A device is a burner from an electric stove. Then the conduction heat is transferred to a pot.
Conduction heat is a method of heat transfer in which the the transfer is takes place by direct contact between objects. From the question , it is clear that, the burner from electric stove transfers energy to a bottom of the pot sitting on it.