Answer: The correct answer is- Oxygen is released as a gas after water is split.
Photosynthesis is a process by which green plants and animals synthesize their own food using CO₂ ( carbon dioxide) and H₂O ( water) in the presence of sunlight. It is divided into two phases that is light dependent ( occurs in thylakoid membrane of chloroplast) and light independent phase ( occurs in stroma of chloroplast)
In the first phase, energy from sunlight gets converted to chemical energy that is ATP and NADPH and water is splitted into electrons, protons and molecular oxygen. This occurs at PS II ( photosystem II), which is a structure present in the thylakoid membrane of chloroplast. The electrons released then participate in the electron transport chain.
Molecular oxygen is released in the atmosphere.