This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hospital waste and disaster management, Occupational health, Subject name: Social & Preventive Medicine
Cause of Farmer's lung- 
Select and explain. 
A. Cotton dust, B. Grain dust, C. Sugarcane dust, D. Iron
B: Grain dust
Answer: B: Grain dust 
Explanation: - farmers lungs is due to the inhalation of mouldy or hay grain dust. - micropolyspora faeni is the main cause of farmer's lung. - repeated attacks cause pulmonary fibrosis, inevitable pulmonary damage and cor pulmonale. Reference: Park's textbook of preventive and social medicine, 23rd edition, pg no:807 <\p>