Explanation:

- Red worms possess a gizzard, which is a muscular structure aiding in grinding food. The gizzard uses tiny soil particles or grit to break down food into smaller, digestible pieces.

- The esophagus is a tube connecting the throat to the stomach, primarily used for transporting food rather than grinding it.

- The intestine is where nutrient absorption takes place, not involved in grinding but rather the digestion and absorption process.

- The crop is a storage area where food is moistened but not ground.