5.16 A power cycle operating between hot and cold reservoirs at 500 K and 300 K, respectively, receives 1000 kJ by heat transfer from the hot reservoir. The magnitude of the energy discharged by heat transfer to the cold reservoir must satisfy (a) QC > 600 kJ, (b) QC ≥ 600 kJ, (c) QC = 600 kJ, (d) QC ≤ 600 kJ.