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': 'All are consequences of edentulism except \nSelect and explain. \nA. Prognathic appearance, B. Thinning of lips, C. Decreased length of lip, D. Increase in columella philtrum angle', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]