JEE Main 2018 Chemistry question

The gas phase reaction 2NO(g) → NO(g) is an exothermic reaction. The decomposition of NO, in equilibrium mixture of NO(g) and NO(g), can be increased by :

• (A)addition of an inert gas at constant pressureCorrect
• (B)lowering the temperature
• (C)increasing the pressure
• (D)addition of an inert gas at constant volume