Explain how living organisms changed the environment during earth's early years

Based on many assumptions, the conditions on nearly earth, some three to four billion years ago, are thought to be much different before from what they are today. The theory called big bang is defined proposing that the earth was once part of a larger particles that coalesced after the universe initial explotion.

Icant be totally sure but i would say with confidence that it is example #1 about cells.