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
Causative organism of Kalahazar is: 
Select and explain. 
A. Plasmodium ovale, B. Leishman donovani, C. Entamoeba histolytica, D. Toxoplasma
B: Leishman donovani
Answer: B: Leishman donovani 
Explanation: None