What gas was depleted (used up) by the time that oxygen became abundant?

Scientists believed that it was HYDROGEN GAS that was used up before the oxygen gas become abundant in the atmosphere. Research shows that, millions of year ago, carbon dioxide was the most abundant gas in the atmosphere and that there is no oxygen at all. As time goes on and the earth mature, oxygen come into existence.

B. would complete your answer. give me brainliest!

The answer is d. when it begins to fall back to the child's hand