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: Pathology
[{'content': 'A patch test is what type of hypersensitivity? \nSelect and explain. \nA. Type 4, B. Type 1, C. Type 2, D. Type 3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: HYPERSENSITIVITY REACTIONS', 'role': 'assistant'}]