Answer: changed by molecular oxygen
Explanation:
Biologically induced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere.
The answer is B cause earth moon and sun combined together creates the greatest gravitational pull and makes tides.
The answer coule be deletion or a mutation
Fire releases carbon dioxide, a key greenhouse gas into the atmosphere. The effect on the environment may be long-lasting and it could damage the surroundings.