Methane, ch4, burns in oxygen gas to form water and carbon dioxide. what is the correct balanced chemical equation for this reaction?

a. ch4 + o ? h2o + co2

b. ch4 + 4o ? 2h2o + co2

c. ch4 + o2 ? h2o + co2

d. ch4 + 2o2 ? 2h2o + co2