This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Yearly vaccination on fixed dates is done for \nSelect and explain. \nA. Polio, B. Malaria, C. Pertusis, D. Tetanus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a (Polio). (Ref. Park, PSM 17th/pg.91)Infectious diseases whose control is solely based on active immunization are: m Measles# Diphtheria# Polio# TetanusThe pulse polio programme involves yearly vaccination below 5 years of age on fixed dates.', 'role': 'assistant'}]