metabolic production of methane production of nitrates from inorganic nitrogen aerobic breakdown of sugars to release energy transformation of light energy into chemical bond energy
I gave my students this multiple choice question: The types of organisms on Earth changed as a result of increased levels of atmospheric oxygen. Which process contributed to this buildup of oxygen in Earth's atmosphere?

Only one answer is correct among these 4 choices:
- metabolic production of methane
- production of nitrates from inorganic nitrogen
- aerobic breakdown of sugars to release energy
- transformation of light energy into chemical bond energy

Could you tell me which one is correct?

transformation of light energy into chemical bond energy