Which of the following is the correct statement of the second law of thermodynamics?
(A) There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy
(B) It is impossible to transfer heat from a body at a lower temperature to a higher temperature, without the aid of an external source
(C) It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
(D) All of the above (Ans)