Heat is d) a measure of thermal energy transferred between two bodies at different temperatures.
Heat refers specifically to the energy that is transferred from one body or system to another due to a temperature difference. It is important to note that while temperature is a measure of the average kinetic energy of particles in a substance, heat is the energy that flows as a result of this difference. When two objects at different temperatures come into contact, energy in the form of heat transfers from the hotter object to the cooler one until thermal equilibrium is achieved. Therefore, heat is fundamentally about the transfer of energy, rather than just a measure of temperature or thermal energy in isolation.