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': 'Down’s cephalometric analysis of a patient reveals a high mandibular plane angle. Which of the following landmarks are used for the construction of the mandibular plane in this analysis? \nSelect and explain. \nA. Go-Me, B. Go-Gn, C. Tangent to the lower most border of the mandible, D. Me-antegonial notch', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tweed and Ricketts- straight line tangent to the lower most border of the mandible.\nDowns- line joining Gonion to menton.\nSteiner- line joining Gonion to gnathion.\nBimler’s line- line joining menton to antegonial notch.\n\nRef: Radiographic cephalometry:Jacobson A', 'role': 'assistant'}]