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': 'Sandfly can fly upto – \nSelect and explain. \nA. 50 yards, B. 100 yards, C. 200 yards, D. 300 yard', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]