For the High Temperature Equilibrium System, 2 H₂ O (G)

For the high temperature equilibrium system, 2 H₂ O (g) 2 H₂ (g) + O₂(g) , what will be the effect on the equilibrium concentration of O₂(g) upon:
(1) adding H₂ O (g) and (2) decreasing the pressure of the system?

A) (1) and (2) increase the concentration of O₂
B) (1) increases while (2) decreases the concentration of O₂
C) (1) decreases while (2) increases the concentration of O₂
D) (1) and (2) decrease the concentration of O₂
E) none of these