question 3 (1 point)\nhow did earths atmosphere obtain breathable oxygen?\no a the ozone layer broke down…

question 3 (1 point)\nhow did earths atmosphere obtain breathable oxygen?\no a the ozone layer broke down into o₂.\no b earth always had freely available oxygen.\no c carbon dioxide deteriorated into oxygen over time.\no d photosynthetic bacteria released oxygen into the atmosphere.

question 3 (1 point)\nhow did earths atmosphere obtain breathable oxygen?\no a the ozone layer broke down into o₂.\no b earth always had freely available oxygen.\no c carbon dioxide deteriorated into oxygen over time.\no d photosynthetic bacteria released oxygen into the atmosphere.

Answer

Brief Explanations:

Photosynthetic bacteria, like cyanobacteria, used photosynthesis to release oxygen. This oxygen - rich atmosphere evolved over time.

Answer:

d. Photosynthetic bacteria released oxygen into the atmosphere.