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
Delhi boil refers to: 
Select and explain. 
A. Solar Keratosis, B. Malignant pustule, C. L. tropica sore, D. Venereal ulcer
C: L. tropica sore
Answer: C: L. tropica sore 
Explanation: Cutaneous leishmaniasis is the most common form of leishmaniasis affecting humans. 
It is a skin infection caused by a single-celled parasite that is transmitted by the bite of a phlebotomine sandfly. 
This disease is considered to be a zoonosis (an infectious disease that is naturally transmissible from animals to humans), with the exception of Leishmania  tropica. 
Other names are Oriental sore, Tropical sore, Chiclero ulcer, Chiclero's ulcer, Aleppo boil, Delhi Boil or Desert boil.

Ref :https://en.wikipedia.org/wiki/Cutaneous_leishmaniasis