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': 'What is the standard dose of PPD for Mantoux test - \nSelect and explain. \nA. 5TU, B. 10TU, C. 15TU, D. 20TU', 'role': 'user'}, {'content': 'Answer: A \nExplanation: <p> A standard 5 tuberculin unit(5 TU) of PPD-S is used in Mantoux test. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:185. <\\p>', 'role': 'assistant'}]