Answer:
C
Extra-large eyes to see in the dark
Step-by-step explanation:
The bathyal zone is the part of the ocean that lies between the mesopelagic zone and the abyssal zone, typically between depths of 200 and 4,000 meters. This zone is characterized by complete darkness, low temperatures, and high water pressure. In such an environment, the ability to make food from sunlight, such as photosynthesis (option B), is not useful, as there is no light available to support this process. Similarly, the ability to digest large plants (option A) is also not useful, as there are few large plants in this zone. Silver skin that reflects heat (option D) is not necessary, as temperature regulation is not a major concern in the bathyal zone. Therefore, the most useful adaptation for an animal living in the bathyal zone would be extra-large eyes to see in the dark (option C). This would enable the animal to detect and avoid predators, find prey, and navigate through the darkness.