A friend of mine stumbled upon this question while revising equilibrium. Apparently the answer is A.
The answer obviously cannot include adding a catalyst. Furthermore, according to le Chatelier's principle, as temperature increases, the side with the endothermic reaction is favoured, in this case 2NO(g). Also, if there is an increase in pressure, the side with fewer moles of gas will be favoured as it consumes more moles of gas. However, as both sides of the reaction have an equal amount of moles of gas, I would believe this to not have any effect and thus answer C. Hence, how come the answer is A?