Correct answer is option C i.e. The equilibrium shifts to the right.
Reason:
Following reaction is involved in present case:
N2 (g) + 3H2 (g) ⇄ 2NH3(g)
Now, according to Le Chatelier's principle, if pressure is increased/decreased in system, the reaction equilibrium will move in direction to minimize this effect. So, if H2 is added in reaction system, it will increase pressure of reaction system. Hence, equilibrium will shift towards right, so as to minimize the effect of increasing pressure.