Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O What mass of oxygen is required to completely react with 20 grams of CH4? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 10 grams O2 B. 20 grams O2 C. 80 grams O2 D. 144 grams O2