1 mole each of `N_2(g)` and `O_2(g)` are introduced in a 1L evacuated vessel at 523 K and equilibrium `N_2(g)+O_(2)ghArr2NO(g)` is established.The concentration of `NO(g)` at equilibrium :
A. Changes on changing volume of vessel
B. Changes on changing temperature
C. Changes on changing pressure
D. Remains same even when a platinum gauze is introduced to catalyse the reaction