13. Which of the following statements about the 2nd law of Thermodynamics is not correct?
(A) In a closed system, the entropy either stays the same or increases with time
(B) There is no perpetual motion machine
(C) The efficiency of any engine operates between two heat reservoir is less or equal to that of a Carnot engine
(D) Heat can never pass from a colder to a warmer body without some other change occurring at the same time
(E) None of the above.