What is the percent-yield of H2 in the reaction below when an equimolar mixture of CH4 and CO2 with an initial total pressure of 20.0 atm reaches equilibrium at 1200. K, at which Kp = 3.548 x 106?

CH_4(g) + CO_2(g) ? 2CO(g) + 2H_2(g)



A. 84.5 %
B. 98.0 %
C. 63.4 %
D. 48.9 %
E. 76.7 %