A 10-cm high and 20-cm wide circuit board houses on its surface 100 closely spaced chips, each generating heat at a rate of 0.08 W and transferring it by convection to the surrounding air at 40°C. Heat transfer from the back surface of the board is negligible. If the convection heat transfer coefficient on the surface of the board is 10 W/m2 • °C and radiation heat transfer is negligible, the average surface temperature of the chips is
(a) 80°C
(b) 54°C
(c) 41°C
(d) 72°C
(e) 60°C