question 12 of 26 what caused the great oxida...

question 12 of 26 what caused the great oxidation event? a. as earth cooled, water vapor released free oxygen and other gases. b. cyanobacteria carried out photosynthesis and released free oxygen. c. gases from lightning strikes changed inorganic compounds into oxygen. d. volcanic eruptions released oxygen and other gases from the interior of earth.

Answer

# Brief Explanations: The great oxidation event was mainly due to cyanobacteria performing photosynthesis and releasing free - oxygen into the atmosphere. Earth cooling did not release free oxygen from water vapor in this context. Lightning strikes changing inorganic compounds into oxygen was not the main cause. Volcanic eruptions did not release oxygen in a way that caused the great oxidation event. # Answer: B. Cyanobacteria carried out photosynthesis and released free oxygen.