Like D. Codon is the answer
It would be D. Water molecules are split apart and the byproduct of that would be the O2. As energy enters the chloroplasts, the energy excited the H2O molecules and causes them to split
Borders are still guarded zealously and fought for - via wars when required and when not required in equal measure. I see nations fighting
over water that preciously scarce resource of the future. I see that terrorists still abound - the Osama Bin Laden types still roam the Earth terrorizing countries and peoples with newer weapons and newer methods of instilling terror. I see that the United States is no longer the sole superpower of the world -- the most powerful country on Earth. I see the most powerful countries dominating the world as being China, India, Brazil and Russia in that order. I see that China and India have become the equivalent of the US and the erstwhile Soviet Union - fighting another Cold War between them and competing for resources and influence around the world.
Carbon dioxide is a byproduct of respiration while oxygen is a byproduct of photosynthesis.
Remember that a byproduct is a secondary product that is made in the synthesis of another. It is unintended and excreted.
