The O₂ evolved during photosynthesis comes from

Solution (By Examveda Team)

The O₂ that evolved during photosynthesis comes from H₂O.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.
Oxygen evolved during this process is evolved from the hydrolysis of water, and the hydrogen freed by the splitting of water is used in the creation of further compounds.