Answer:
C. thermal energy
Step-by-step explanation:
Thermal energy of the system or internal energy of the system is defined as the sum of kinetic energy of all the molecules of the system
As we add the kinetic energy of all the molecules then the sum of this kinetic energy is related to the temperature of the system
It is given as

so here we can say that thermal energy would be the sum of kinetic energy of all the system molecules and it measures the energy related to motion of the system molecules
so correct answer would be
C. thermal energy