In a Steam Engine,steam at 140°C in a Turbine Does

Multiple Choice

In a steam engine,steam at 140°C in a turbine does work on an external system,and the steam leaves the turbine at 100°C.The efficiency of the steam engine is 5%.The relevant physical principle is

A) the first law of thermodynamics.
B) the second law of thermodynamics.
C) specific heat capacity.
D) operation of a heat pump.
E) none of the above.