Air at a Total Pressure of 85 KPa, 15°C, and 70

Air at a total pressure of 85 kPa, 15°C, and 70 percent relative humidity is heated and humidified to 25°C and 60 percent relative humidity by introducing water vapor. If the mass flow rate of dry air is 4.6 kg/s, the rate at which steam is added to the air is

A) 0.025 kg/s
B) 0.0054 kg/s
C) 3.22 kg/s
D) 0 kg/s
E) 0.18 kg/s