Final answer:
The alimentary canal runs from the mouth to the anus and is essential for nourishing the body through the digestion and absorption of nutrients.
Step-by-step explanation:
The alimentary canal, also known as the gastrointestinal (GI) tract, contains the hollow organs that run from your mouth to your anus. The correct answer to the student's question is option b. Mouth; anus. These organs include the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Each section of the alimentary canal has a specific role in nourishing the body and processing food; from the intake in the mouth to the elimination of wastes through the anus.