During photosynthesis reaction taking place in plants, which of the following changes occur

The carbon in $C{O}_2$ is $sp$ hybrid but in carbohydrates mostly $s{p}^3$ or $s{p}^2$ in functional groups such as aldehyde or ketonic group. The oxidation state carbon in $C{O}_2$ is $+4$ but in carbohydrate is zero. So it is reduction. The oxidation state of oxyen in $H_{2}O$ is $-2$ but the oxygen liberated have oxidation state zero. Also $s{p}^3$ hybrid oxygen changes to normal oxygen in $O_2$