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: Microbiology
Maltworker's lung is caused by: 
Select and explain. 
A. Aspergillus clavatus, B. Aspergillus fumingatus, C. Pseudomonas, D. Micropolyspora faeni
A: Aspergillus clavatus
Answer: A: Aspergillus clavatus 
Explanation: Aspergillus clavatus