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: Dental
[{'content': 'Angulation of bone in lower molar area is about: \nSelect and explain. \nA. 5 degrees, B. 10 degrees, C. 15 degrees, D. 20 degrees', 'role': 'user'}, {'content': 'Answer: D \nExplanation: In the posterior mandible, the submandibular fossa mandates implant placement with increasing angulation as it progresses distally. Hence in the second premolar region, the angulation may be 10 degrees to a horizontal plane; in the first molar area, 15 degrees; and in the second molar region, 20 to 25 degrees.', 'role': 'assistant'}]