For a chemical reaction, ΔG is always less than zero i.e., (ΔG<0) for a spontaneous process. The reaction can be expressed as follows ΔG=ΔH−TΔS=(−) ve Thus, for the ΔG to be (−) ve at all temperature i.e., under all conditions. ΔH must be (−) ve and T\Δ S must be (+) ve so that ΔG remain (−) ve Hence, option (c) is the correct answer.