The correct answer is C. To store gastroliths that physically grind up food.
Explanation
The gizzards, are a special part of the digestive system of some animals such as birds, fish, and reptiles whose main function is to crush the food that the animal ingests, for this task, the gizzards contain in their interior gastroliths, a kind of polished stones, that grinds the food that the animal eats. The gizzards represent an important part for these animals because many of them do not have teeth to crush their food and feed on it. So, the correct answer is C. To store gastroliths that physically grind up food.
