aSteam enters a turbine steadily at 4 MPa and 4008C and exits at 0.2 MPa and 150°C in an environment at 25°C. The decrease in the exergy of the steam as it flows through the turbine is
(a) 58 kJ/kg
(b) 445 kJ/kg
(c) 458 kJ/kg
(d) 518 kJ/kg
(e) 597 kJ/kg