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': 'Which of the following is known as eighth day disease? \nSelect and explain. \nA. Puerperal tetanus, B. Tetanus neonatorum, C. Varicella, D. Measles', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Tetanus neonatorum is known as eighth day disease. The common cause of neonatal tetanus is infection of umbilical stump and signs usually appear about the 7th day. Ref: Park 21st edition, page 286.', 'role': 'assistant'}]