Air (at atmospheric pressure) at a dry bulb temperature of 400C and wet bulb temperature of 200C is humidified in an air washer operating with continuous water recirculation. The wet bulb depression (i.e. the difference between the dry and wet bulb temperatures) at the exit is 25% of that at the inlet. The dry bulb temperature at the exit of the air washer is closed to
(a) 100C (b) 200C
(c) 250C (d) 300C