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': 'The disadvantage of three fourth crown \nSelect and explain. \nA. Compromised esthetics, B. More tooth reduction, C. Inadequate retention, D. Biomechanical compatibility', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]