Final answer:
The voltage difference in the electrical system is analogous to the temperature difference in the heat transfer system.
Step-by-step explanation:
The voltage difference in the electrical system is analogous to c. the temperature difference in the heat transfer system. This is because, just like voltage causes the flow of electric current in a circuit, temperature difference causes the flow of heat in a heat transfer system. In both cases, there is a driving force that facilitates the transfer of energy.