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
Angulation of bone in lower molar area is about: 
Select and explain. 
A. 5 degrees, B. 10 degrees, C. 15 degrees, D. 20 degrees
D: 20 degrees
Answer: D: 20 degrees 
Explanation: 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.