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: Radiology
[{'content': 'An airline flight of 5 hours in the middle latitudes at an altitude of 12 km may result in an exposure of _____\xa0\xa0µSv. \nSelect and explain. \nA. 25, B. 50, C. 250, D. 100', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Directly picked from White and Pharoah:\n"An airline flight of 5 hours in the middle latitudes at an altitude of 12 km may result in an exposure of about 25 µSv".\nWhite and Pharoah\'s Oral\xa0 Radiology Principles and Interpretation 8th edition', 'role': 'assistant'}]