For which of the following equilibrium systems will the equilibrium position temporarily shift in the forward direction when the pressure is increased?
a) H2(g) + Cl2(g) <----->2HCl (g)
b) CH4 (g) + 2H2S (g)<------> CS2 (g) + 4H2 (g)
c) CO (g) + H2O (g) <-----> CO2 (g) + H2 (g)
d) 2NO2 (g) + 7H2 (g)2NH3 (g) + 4H2O (g)