This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'For every clinical case of poliomyelitis subclinical cases are - \nSelect and explain. \nA. 500 in children and 75 in adults, B. 500 in children and 25 in adults, C. 250 in children and 25 in adults, D. 1000 in children and 75 in adults', 'role': 'user'}, {'content': 'Answer: D \nExplanation: It is estimated that for every clinical case, there may be 1000 subclinical cases in children and 75 in adults. Ref :PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page:205', 'role': 'assistant'}]