Which of these statements are implied by the second law of thermodynamics?
(a) The entropy of an engine (including its fuel and/or heat reservoirs) operating in a cycle never decreases.

(b) The increase in internal energy of a system in any process is the sum of heat absorbed plus work done on the system.

(c) A heat engine, operating in a cycle, that exhausts no heat to the low-temperature reservoir is impossible.

(d) Both (a) and (c). 

(e) All three [(a), (b), and (c)].