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': 'Dehydration is the common concern in elderly edentulous patients because of \nSelect and explain. \nA. Reduced ability to sense thirst, B. Poor absorption of fluids, C. Vitamin deficiency, D. Osteopenia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]