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': 'Pitchfork analysis is given by: \nSelect and explain. \nA. Pitchfork (1987), B. Pitchfork (1986), C. Johnston (1985), D. Pancherz (1986)', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pitchfork analysis\n\nThe pitchfork analysis was developed by Johnston in 1985.\nGrowth and displacement of the maxilla and mandible are measured relative to the cranial base\xa0(SE).\n\nThe change in the position of the upper and lower molars and incisors are measured relative to the\xa0basal bone. All measurements are made parallel to a mean functional occlusal plane. The algebraic\xa0sum of various skeletal and dental changes is equal to the treatment change in the molar relationship and incisal overjet.', 'role': 'assistant'}]