The term “Dark Oxygen”, recently seen in news, refers to:
1
Oxygen produced in the deep ocean by polymetallic nodules without the involvement of light or photosynthesis.
2
Oxygen trapped in ancient ice cores, studied to understand past climate conditions.
3
Oxygen released by undersea volcanic activity during eruptions.
4
Oxygen produced by bioluminescent organisms in the deep ocean.
5
Question Not Attempted