Choose the correct order of events in light reaction.

I) ATP and NADPH formation

II) Water Splitting

III) Oxygen release

IV) Light absorption

1)	III	IV	II	I
2)	IV	III	I	II
3)	IV	II	III	I
4)	II	III	IV	I

The correct order of events in the light reactions of photosynthesis is as follows:

IV) Light absorption: The process begins with the absorption of light by the pigments (e.g., chlorophyll) in the thylakoid membranes of the chloroplasts.

II) Water Splitting: The absorbed light energy is used to split water molecules into oxygen (O₂), protons (H⁺ ions), and electrons (e-). This process occurs in Photosystem II (PS II) and is essential for generating the electrons needed to drive the electron transport chain.

III) Oxygen release: As a byproduct of water splitting in Photosystem II, oxygen molecules (O₂) are released into the atmosphere. This is one of the important contributions of light reactions to the environment, providing oxygen for various forms of life on Earth.

I) ATP and NADPH formation: The excited electrons generated from water splitting are passed through the electron transport chain, releasing energy in the process. This energy is used to pump protons across the thylakoid membrane, creating a proton gradient. The potential energy of this gradient is harnessed by ATP synthase to produce ATP (adenosine triphosphate). Additionally, the electron transport chain transfers electrons to Photosystem I (PS I), where they are re-energized and ultimately used to reduce NADP⁺ to NADPH (nicotinamide adenine dinucleotide phosphate).