Bro if u dont know this answer you better pay attention in class cause this is the easiest thing i have ever seen. And if you cant find the answer in your class book come back in here and i will hook you up.<span />
Answer:
water act as a reactant in light reaction.
Explanation:
Water undergo hydrolysis in presence of sunlight to form proton(H+) and hydroxyl ion(OH-) ion. The OH- ion liberates electron to reaction center of photosystem 1 thereby exciting the later .The excited photosystem then donates that extra electron to the primary electron acceptor and from the primary electron acceptor the electron moves through various electron carriers to generate ATP .
Basically water act as reducing agent in photosynthesis process.
I think it A because Cyanobacteria absorb co2 from the atmosphere and then release oxygen To the atmosphere