Which one is incorrect statement of the second law of thermodynamics ?
A. It is impossible for a cyclic process to transfer heat from a system at a lower temperature to one at a higher temperature without converting some work to heat
B. It is impossible to convert heat completely into equivalent amount of work without producing changes elsewhere
C. Every perfect machine working reversibly between the same temperature of source and sink have the same efficiency whatever be the nature of the substance used
D. Heat engine can be made 100% efficient
