The partial pressure of water vapour (in kPa) in the moist air entering the compressor is closest to

Question

Moist air at a pressure of 100kPa is compressed to 500kPa and then cooled to 35⁰C in an after cooler. The air at the entry to the after cooler is unsaturated and become just saturated at the exit of the after cooler. The saturation pressure of water at 35⁰C is 5.628 kPa. The partial pressure of water vapour (in kPa) in the moist air entering the compressor is closest to                                                                                                               

      (a) 0.57                                                               (b) 1.13

      (c) 2.26                                                               (d) 4.52