The heat transfer from the turbine casing to the surroundings is equal to

Question

A steam turbine receives steam steadily at 10 bar with an enthalpy of 3000 kJ/kg and discharges at 1 bar with an enthalpy of 2700 kJ/kg. The work output is 250 kJ/kg. The changes in kinetic and potential energies are negligible. The heat transfer from the turbine casing to the surroundings is equal to                         

      (a) 0 kJ                                                               (b) 50 kJ            

      (c) 150 kJ                                                           (d) 250 kJ