In which part of the ocean do the greatest number of organisms live? A. in the deep zone to escape predators B. near the shore to burrow in the sand C. close to the surface to be near the largest food source D. in the open ocean to regulate their bodies in cooler temperatures

The greatest number of organisms live close to the surface of the ocean to be near the largest food source. This is because sunlight, which is necessary for photosynthesis, penetrates only a limited distance below the surface of the water. Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the aid of chlorophyll pigments. This process produces organic compounds (which serve as a food source for other organisms) and oxygen, which is a byproduct. The zone near the surface of the ocean where photosynthesis can occur is called the euphotic zone. Therefore, the correct answer is C. close to the surface to be near the largest food source.