This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiration, Subject name: Pathology
Which of the following is a causative agent of Farmer's Lung? 
Select and explain. 
A. Thermophilic Actinomycetes, B. Aspergillus Fumigatus, C. Actinobacter, D. Aspergillus Flavus
A: Thermophilic Actinomycetes
Answer: A: Thermophilic Actinomycetes 
Explanation: Ref: Harrison 20th edition, P 1970Farmers lung is a hypersensitivity pneumonitis which is caused by thermophilic actinomycetes. The same organism grows on sugarcane dust and is the antigen leading to Bagassosis.DiseaseAntigenSourceFarming/Food ProcessingFarmer's lungThermophilic Actinomycetes (e.g., Saccharopolyspora rectivirgula); fungusGrain, moldy hay, silage SugarcaneBagassosisThermophilic actinomycetes