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
Kala-azar is not responding to primary treatment. The treatment should now consist of- 
Select and explain. 
A. Double dose of antimony, B. Amphotericin - B, C. Ketoconazole, D. Splenectorny
B: Amphotericin - B
Answer: B: Amphotericin - B 
Explanation: None