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: Medicine
All of the following are characterized by upper lobe Fibrosis except 
Select and explain. 
A. Silicolis, B. Busulphan, C. Cystic Fibrosis, D. Histoplasmosis
B: Busulphan
Answer: B: Busulphan 
Explanation: Busulphan causes lower lobe fibrosis.