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: Dental
Groove sign is seen in – 
Select and explain. 
A. Donovanosis, B. LGV, C. Chancroid, D. Genital herpes
B: LGV
Answer: B: LGV 
Explanation: Groove sign of Greenblatt' is pathognomonic of LGV → when inguinal lymph nodes are enlarged, they are separated by Poupart's ligment, producing a groove.