Answer
See the detailed answer below.
Work Step by Step
a) The temperature $T$ is a state variable of a system that quantifies the hotness or the coldness” of the system. The temperature difference $\Delta T$ is used to measure the thermal interaction between two systems which is amount of heat energy that transferred between these two systems.
b) Hheat $Q$ is not a state variable and hence is not a property of the system. The heat is the amount of energy that moves between the systems during a thermal interaction.
c) Thermal energy $E_{th}$ is a state variable of a system that measures the total energy associated with the particles in a system.
From all the above, temperature is a property of a system, while heat and thermal energy describe the interactions of the system with its environment. Heat is the transfer of thermal energy between two systems due to a temperature difference, and thermal energy is the total energy associated with the particles in a system