For vaporization of water at 1 atmospheric pressure. the values of ΔH and ΔS are 40.63 kJ mol-1 and 108.8 JK-1 mol-1, respectively. The temperature when Gibb's energy change (ΔG) for this transformation will be zero, is
(a) 273.4 K
(b) 393.4 K
(c) 373.4 K
(d) 293.4 K