This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Dermatitis, Subject name: Dental
[{'content': 'Patch test is read after \nSelect and explain. \nA. 2 hours, B. 2 days, C. 2 months, D. 2 weeks', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref Harrison20th edition pg 2345', 'role': 'assistant'}]