What are two things that ligth energy has a role in photosyntesis

During photosynthesis, light energy is needed for two reactions:

1. The removal of electrons from water molecules. This process of taking away electrons is known as oxidation. Plants use light energy to propel oxidation of water.

2. Transfer of electrons to NADP+ . This process of adding electrons is known as reduction. Plants use  light energy to carry out reduction of NADP+.

These two reactions lead to formation of chemical energy. This energy is then used in the Calvin cycle to synthesize a three-carbon sugar from carbon dioxide that has been captured from the atmosphere.

the answer is c.the valence of the atoms combine .