Where does the O2 come from that is essential for the proper functioning of oxidative phosphorylation?

Light reactions of photosynthesis

Dark reactions of photosynthesis

Where does the O2 come from that is essential for the proper functioni

1.	Where does the O2 come from that is essential for the proper functioning of oxidative phosphorylation?
A.	Light reactions of photosynthesis
B.	Fermentation
C.	Carbon fixation
D.	Dark reactions of photosynthesis
Answer» B. Fermentation