In the equation for calculating the overall heat transfer coefficient for a tubular heat exchanger, what does the term (1/hi/Aj) represent? O the thermal resistance due to convection heat transfer in the fluid outside the tube O the thermal resistance due to conduction through the tube wall O the thermal resistance due to fouling on the inside tube the thermal resistance due to convection of the fluid flowing through the inside tube O none of the above the thermal resistance due to foiling on the outside of the tube