The correct option is A N2O4(g)⇌2NO2(g)
As per Le- chatelier principle,
Doubling the volume would reduce the pressure and shift the equilibrium in the direction where there is more number of moles of gases.
So, in option (a), the equilibrium will shift to the right.
In option (b), the reaction will favour formation of reactants.
In option (c), number of moles of reactants is equal to number of moles of products.