This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Which is done even after control of disease? \nSelect and explain. \nA. Surveillance, B. Vaccination, C. Chemoprophylaxis, D. Prolonged treatment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: A (Surveillance) Ref: Park v Preventive and Social Medicine, 22nd edition. Pg 118Explanation:Surveillance is continuous scrutiny of occurrence of disease or health related events to take action.So, even after control of disease, one needs to keep an eye on the occurrence of disease, so that it is identified in time to take action.All other options are distracters.', 'role': 'assistant'}]