The event that does not occur in photosynthesis is

Question

$\begin{array}{1 1} (a)\; \text{Absorption of light energy by chlorophyll } \\ (b)\; \text{Reduction of $CO_2$ to carbohydrates} \\ (c)\; \text{Oxidation of carbon to $CO_2$} \\ (d)\; \text{Conversion of light energy to chemical energy} \end{array}$