This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'Rejecting a null hypothesis when it is true is called as? \nSelect and explain. \nA. Type 1 error, B. Type 2 error, C. Type 3 error, D. Type 4 error', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]