Photo-oxidation of water in photosynthesis is in the association with:

A. Cytochrome b6
B. Pigment system- I
C. Pigment system- II
D. Plastocyanin

The photo-oxidation of water in photosynthesis is associated with the pigment system II (PSII). PSII is responsible for the initial step in the light-dependent reactions of photosynthesis, where water molecules are split into oxygen, electrons, and protons. This process is known as photolysis of water.

During PSII, light energy is absorbed by chlorophyll molecules, and this energy is used to excite electrons within the chlorophyll molecules. These excited electrons are then transferred through a series of electron carriers, including plastocyanin and cytochrome
�
6
b6f, ultimately leading to the production of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate).

Plastocyanin and cytochrome
�
6
b6f are electron carriers that facilitate the transfer of electrons between different components of the photosynthetic electron transport chain. However, the direct association with the photo-oxidation of water occurs at PSII.