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
Treatment of choice in hairy cell leukemia is - 
Select and explain. 
A. Steroids, B. Cladiribine, C. Splenectomy, D. Pentostatin
B: Cladiribine
Answer: B: Cladiribine 
Explanation: None