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
[{'content': 'Which of the following is a causative agent of Visceral Leishmaniasis? \nSelect and explain. \nA. Leishmania braziliensis, B. Leishmania panamensis, C. Leishmania donovani, D. Leishmania major', 'role': 'user'}, {'content': "Answer: C \nExplanation: Visceral Leishmaniasis (kala-azar in Hindi) is caused by the L. donovani complex, which includes L. donovani (anthroponotic transmission) and L. infantum or L. chagasi (zoonotic transmission). Prevalence: India and neighboring Nepal, Bangladesh, Sudan, and Brazil are the four largest foci of VL and account for 90% of the world's VL burden, with India the worst affected. Ref: Sundar S. (2012). Chapter 212. Leishmaniasis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.", 'role': 'assistant'}]