A liquid metal is flowing inside of a 3 cm diameter pipe, 5 meters long with an entering temperature of 400 °C. The wall temperature is maintained at 500 °C and the mass flow rate of the metal is 50 kg/min. ?-5, 500 kg/m3 , Pr - 0.0025, ?- 0.0025 N-s/m2 , k- 6.2 W/m-K, ?? 0.33 kJ/kg-K. The exit temperature of the liquid metal is most nearly: A. 430 B. 445 ?. 465 D. 500