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: Skin
Groove sign of greenbalt is seen in ? 
Select and explain. 
A. LGV, B. Donovanosis, C. Chancroid, D. Genital Herpes
A: LGV
Answer: A: LGV 
Explanation: Ans. is 'a' i.e., LGV Groove sign of Greenblatt' is pathognomonic of LGV when inguinal lymph nodes are enlarged, they are separated by Poupa's ligment, producing a groove.