This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'What is the approximate penetrating ability of alpha paicle radiation at tissue level - \nSelect and explain. \nA. 0.05 mm, B. 0.10 mm, C. 1.50mm, D. 2.00 mm', 'role': 'user'}, {'content': "Answer: A \nExplanation: Park's textbook of preventive and social medicine 23rd edition. * Alpha paicles approximate penetrating ability - 4cm - 0.05 cm - 0", 'role': 'assistant'}]