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
Causative agent of Farmer's lung is: 
Select and explain. 
A. Themophilus actinomycetes, B. Aspergillus, C. Penicilliumglabrum, D. Rhizopus
A: Themophilus actinomycetes
Answer: A: Themophilus actinomycetes 
Explanation: Ans. (a) Themophilus actinomycetes(Ref: Robbins 9th/pg 689; 8th/pg 687)In farmer's lung, inhalation of proteins, such as thermophilic actinomyces bacteria and fungal spores that are present in moldy bedding and feed, are most commonly responsible for the development of Hypersensitivity pneumonitis.