In this equation for photosynthesis where does the first reactant come from and what happens to it in the photosynthetic process?

6co2 + 6h2o > c6h12o6 + 6o2

a - carbon dioxide comes from the air and is broke down in the calvin cycle.

b - water is split to drive nadp to nadph conversion, which is formed in the calvin cycle.

c - oxygen is released as a gas after water is split.

d - glucose is formed right after the calvin cycle