Splitting of water is associated with the inner surface of thylakoid membrane in photosynthesis. The process of photosynthesis takes place in the chloroplasts of green plants, which contain stacks of membranes called thylakoids. The thylakoid membranes are where the light-dependent reactions of photosynthesis occur, and they contain the pigments and proteins needed for this process. The splitting of water is a crucial step in the light-dependent reactions, as it provides the electrons needed to generate ATP and NADPH, which are used in the subsequent steps of photosynthesis.

The process of splitting water can be broken down into the following steps:

1. Absorption of light energy: Light energy is absorbed by the pigments in photosystem II, which are located on the inner surface of the thylakoid membrane.

2. Excitation of electrons: The absorbed light energy excites electrons in the pigments, which are then transferred to a molecule called the primary electron acceptor.

3. Splitting of water: The electrons that were transferred to the primary electron acceptor are replaced by electrons from water molecules, which are split into oxygen, hydrogen ions, and electrons. This process is catalyzed by an enzyme called water-splitting complex, which is also located on the inner surface of the thylakoid membrane.

4. Generation of ATP and NADPH: The electrons that were transferred to the primary electron acceptor are used to generate ATP and NADPH, which are then used in the dark reactions of photosynthesis to synthesize glucose.

In conclusion, the splitting of water is associated with the inner surface of thylakoid membrane in photosynthesis, and is a crucial step in the light-dependent reactions that generate ATP and NADPH.

D) : Light reactions occur inside the thylakoids, especially those of grana region. It involves two types of reactions photolysis of water and production of assimilatory power. The phenomenon of breaking up of water into hydrogen and oxygen in the illuminated chloroplasts is called photolysis or photocatalytic splitting of water. Water splitting complex is associated with the PSII, which itself is physically located on the inner surface of thylakoid membrane.