Which takes place as water cycles from the bottom of the pot toward the top?

a. thermal energy is transferred.

b. water molecules gain kinetic energy.

c. chemical energy is transferred.

d. water molecules gain thermal energy.

The option that takes place as water cycles from the bottom of the pot toward the top is that A. thermal energy is transferred. 
As the pot gets warmer and warmer, the heat flows everywhere inside the pot, ultimately reaching the top, and heating the water at the top as well. There is no chemical energy here, and molecules don't gain thermal energy, it is just transferred to the top of the pot.