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': 'Ideal chin throat angle is: \nSelect and explain. \nA. 120o, B. 70o, C. 130o, D. 90o', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Neck–chin–angle\nCervicomental angle should be approximately 90 degrees. The angle is more obtuse in females as compared to males. The soft tissues sag in older individuals and contributes to less than ideal submental form.\nLip–chin–throat angle\nThe angle between the lower lip and deepest point along the neck chin contour should be approximately 90 degrees.\nAn obtuse angle is unaesthetic and more so as the angle increases. This often reflects:\n\nChin deficiency\nRetropositioned mandible\nLower lip procumbency\nExcessive submental fat\nLow hyoid bone position', 'role': 'assistant'}]