This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacterial infections, Subject name: Dental
Type-I lepra reaction is commonly seen in: 
Select and explain. 
A. Histoid Leprosy, B. Lepromatous Leprosy, C. Borderline tuberculoid leprosy, D. Polyneuritic leprosy
C: Borderline tuberculoid leprosy
Answer: C: Borderline tuberculoid leprosy 
Explanation: type 1 reaction /reversal reaction is a delayed hypersensitivity reaction associated with a rapid increase in specific CMI activity against M.leprae. It usually occurs in borderline types of leprosy, (BB>BT >BL)characteristically associated with immunological instability. Page no.2046Reference IADVL's concise textbook of dermatology