Which answer below is not a statement of the second law of thermodynamics? a. Real processes proceed in a preferred direction. b. In theory, heat engines working in a cycle employ reversible processes. c. The entropy of the universe increases in all natural processes d. Energy does not flow spontancously by heat from a cold to a hot reservoir. You cannot construct a heat engine operating in a cycle that does nothing but take heat from a reservoir and perform an equal amount of work