This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Difficult oral intubation may be associated with all except: \nSelect and explain. \nA. Receding lower jaw, B. Poor mobility of mandible, C. Protruding upper incisor tooth, D. Decreased alveolar mental distance', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Oral tracheal intubation is commonly employed in the administration of general anesthesia. Difficult intubation is expected in: 1. Limited neck extension. 2. Limited temporomandibular joint range of motion. 3. Massive obesity. 4. Prominent maxillary teeth. 5. Broken or loose maxillary teeth. 6. Fragile maxillary dental work. 7. Macroglossia. 8. Tonsillar pillars not visualized. 9. Anterior larynx 10. Rheumatoid involvement of larynx 11. Airway edema. 12. Intrinsic or extrinsic pathology eg. Tumor, abscess, hematoma, or foreign body 13. Active bleeding in airway.', 'role': 'assistant'}]