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: Social & Preventive Medicine
[{'content': 'World Health Day of WHO is on \nSelect and explain. \nA. 7 April, B. 10 April, C. 11 April, D. 15 April', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]