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': 'What does correlation coefficient of 0.5 indicate \nSelect and explain. \nA. Confidence interval of 95 %, B. Weak association, C. Not statistically significant, D. Good association', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ref:Park's Textbook of Preventive and Social Medicine 25th Ed", 'role': 'assistant'}]