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': 'Power is the ability to \nSelect and explain. \nA. Reject true null hypothesis, B. Reject false null hypothesis, C. Accept true null hypothesis, D. Accept false null hypothesis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Power is the probability of rejecting the null hypothesis when, in fact, it is false. Power is the probability of making a correct decision (to reject the null hypothesis) when the null hypothesis is false. Power is the probability that a test of significance will pick up on an effect that is present. Ref :', 'role': 'assistant'}]