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': "Farmer's lung Is caused due to exposure to? \nSelect and explain. \nA. Bacillus subtilis, B. Thermoactinomyces sacchari, C. Aspergillus fumigatus, D. Penicillium nalgiovense", 'role': 'user'}, {'content': "Answer: B \nExplanation: Farmer's lung is a hypersensitivity pneumonitis caused by the inhalation of proteins,such as thermophilic bacteria and fungal spores that are present in moldy bedding and feed.Thermophilic actinomycetes acts as the antigen,producing cell mediated hypersensitivity. Reference:Harrison's medicine-18th edition,page no:2116.", 'role': 'assistant'}]