In Boiling a Pot of Water on an Electric Stove,at

In boiling a pot of water on an electric stove,at what step is conduction the process for heat transfer?

A) when heat from the stove is transferred to the handle
B) when heat is transferred through the bottom of the pot
C) when heated water from the bottom of the pot rises
D) when cooler water at the surface sinks
E) when some of the water evaporates into the air