Which statement best describes how the mouth and esophagus contribute to digestion before chyme reaches the stomach?

• A. The mouth chemically digests proteins with pepsin and mechanically propels food to the esophagus where segmentation completes digestion
• B. The mouth emulsifies fats using bile-like secretions and the esophagus begins absorption of monosaccharides across its mucosa
• C. The mouth performs mechanical breakdown by chewing and begins chemical digestion with salivary amylase and some lipase; the esophagus propels the resulting bolus to the stomach by coordinated peristaltic waves
• D. The mouth is solely a sensory organ that wets food with saliva but does not introduce enzymes, while the esophagus both digests carbohydrates and stores food

Answer: (C)