The chemical reaction : `BaO_(2(s))hArrBaO_((s))+1/2O_(2(g)),DeltaH=+ve.` In equilibrium condition, pressure of `O_(2)` depends upon
A. Increase mass of BaO
B. Increase mass of `BaO_(2)`
C. Increase in temperaturee
D. Increase mass of `BaO_(2)` and BaO both