This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
A 50-year-old male had fever for 1 week, abdominal distention and loss of appetite. It is not responding to antibiotics and antimalarials. Widal test is negative but RK39 dipstick test was positive. Which drug can be used? 
Select and explain. 
A. Bedaquiline, B. Linezolid, C. Fluconazole, D. Amphotericin B
D: Amphotericin B
Answer: D: Amphotericin B 
Explanation: Ans. (D) Amphotericin B(Ref: KDT 8th/902)RK 39 dipstick test is positive in infection with Leishmania. So, it is a case of visceral Leishmaniasis or Kala azar. The drug of choice is amphotericin B.