Final answer:
After 3 hours of sunlight exposure, the leaves submerged in water are photosynthesizing and producing oxygen.
Step-by-step explanation:
After 3 hours of sunlight exposure, the leaves submerged in water are photosynthesizing and producing oxygen. Sunlight is a crucial component for photosynthesis, a process in which plants use light energy to convert carbon dioxide and water into glucose and oxygen. The oxygen produced during photosynthesis is released as a byproduct.