For the given series of reaction,
`4NH_(3)(g) + 5O_(2)(g) rarr 4NO(g) + 6H_(2)O(l)`
`2NO(g) + O_(2)(g) rarr 2NO(g) +O_(2)(g) rarr 2NO_(2)(g)` If 20 ml of `NH_(3)` is mixed with 100 ml of `O_(2)` .Volume contraction at the completion of above reaction is:
A. 20 ml
B. 85 ml
C. 35 ml
D. 100 ml
