What Will Be the Coefficient for NH₃ When the Following $\rightarrow$

Multiple Choice

What will be the coefficient for NH₃ when the following reaction is balanced?
NH₃(g) + O₂(g) $\rightarrow$ N₂(g) + H₂O(l)

A) 1
B) 3
C) 4
D) 5
E) none of these