Sulfur Dioxide, Gaseous Water, and Oxygen Gas React to Prepare $\times$

Sulfur dioxide, gaseous water, and oxygen gas react to prepare sulfuric acid in the following unbalanced equation. Under equilibrium conditions, the partial pressures of the components are P_SO2 = 0.1 atm, P_H2O = 0.05 atm, P_O2 = 0.25 atm, P_H2SO4 = 2.75 atm.
What is the value of the equilibrium constant, K_p, for the reaction?

A) 3.30 $\times$ 10^-4
B) 5.00 $\times$ 10^-4
C) 2.20 $\times$ 10³
D) 3.03 $\times$ 10³
E) 1.21 $\times$ 10⁶