Nitric Oxide Is Formed in Automobile Exhaust When Nitrogen and Oxygen

Nitric oxide is formed in automobile exhaust when nitrogen and oxygen in air react at high temperatures. The equilibrium constant K_p for the reaction is 0.0025 at 2127 $\degree$ C. If a container is charged with 8.00 atm of nitrogen and 5.00 atm of oxygen and the mixture is allowed to reach equilibrium, what will be the equilibrium partial pressure of nitrogen?

A) 0.16 atm
B) 0.31 atm
C) 3.1 atm
D) 7.7 atm
E) 7.8 atm