High Respiration When Did The Level Of Oxygen In Earth's Atmosphere Become High Enough To Sustain Aerobic Respiration?

When did the level of oxygen in Earth's atmosphere become high enough to sustain aerobic respiration? - high respiration

a. 1.5 billion years ago

b. Before 2.7 billion years

c. 3.5 billion years

d. 2.5 billion years

e. 1,0 Milliarden Jahre