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': 'Shade selection is done with in how much time to avoid fatigue of eyes? \nSelect and explain. \nA. 5 seconds, B. 10 seconds, C. 15 seconds, D. 20 seconds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]