Hot water (cp = 4.179 kJ/kg·K) flows through a 80-m·long PVC (k = 0.092 W/m·K) pipe whose...

Hot water (cp = 4.179 kJ/kg·K) flows through a 80-m·long PVC (k = 0.092 W/m·K) pipe whose inner diameter is 2 cm and outer diameter is 2.5 cm at a rate of 1 kg/s, entering at 40°C. If the entire interior surface of this pipe is maintained at 35°C and the entire exterior surface at 20°C, the outlet temperature of water is

(a) 35°C

(b) 36°C

(c) 37°C

(d) 38°C

(e) 39°C