Step-by-step explanation:
Photosynthesis primarily occurs in the photic zone. This is the uppermost layer of water or the upper layer of soil, where sunlight can penetrate. In this zone, light is available for photosynthetic organisms, such as plants, algae, and some bacteria, to convert sunlight into chemical energy through the process of photosynthesis. The aphotic zone refers to regions where light is absent, while the abyssal zone refers to the deepest part of the ocean, which is typically beyond the reach of sunlight.