Cold water (c_p = 4.18 kJ/kg · K) enters a counter flow heat exchanger at 18°C at a rate of 0.7 kg/s where it is heated by hot air (c_p = 1.0 kJ/kg?K) that enters the heat exchanger at 50°C at a rate of 1.6 kg/s and leaves at 25°C. The maximum possible outlet temperature of the cold water is
(a) 25.0°C

(b) 32.0°C

(c) 35.5°C

(d) 39.7°C

(e) 50.0°C