Multiple Choice
According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?
A) Oxygen was removed from the atmosphere by chemical reactions with surface rocks as quickly as it was released by life.
B) Early forms of animal life consumed the oxygen released by plants during the first billion years of life on Earth.
C) Early life did not release oxygen, and oxygen releasing organisms didn't evolve for a billion years after the earliest life.
D) Oxygen was removed from the atmosphere by dissolving in the ocean as quickly as it was released by life.
Correct Answer:

Verified
Correct Answer:
Verified
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