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: Pathology
[{'content': 'Bysinnosis is caused by: March 2010 \nSelect and explain. \nA. Bagasse, B. Mold hay, C. Cotton, D. Bird droppings', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Cotton', 'role': 'assistant'}]