This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Pneumoconiosis is caused due to inhalation of dust within the size range of - \nSelect and explain. \nA. 0.5-2.5 microns, B. 3-6 microns, C. 6.5-8 microns, D. 10-20 microns', 'role': 'user'}, {'content': "Answer: A \nExplanation: Paicle size of air contaminants must be considered in pneumoconiosis .Paicles >10-15 microns do not penetrate beyond the nose and throat.Paicles 2.5-10 microns contain crustal elements such as silica,aluminium,and iron.These paicles mostly deposit high in the tracheobronchial tree.Fine -mode fraction include paicles less than 2.5 microns,which are carried to the lower airways and produces pneumoconiosis. Reference:Harrison's medicine-18th edition,page no:2122.", 'role': 'assistant'}]