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
Frei's test is diagnostic of: 
Select and explain. 
A. Lymphogranuloma venerum, B. Lymphogranuloma inguinale, C. Donovanosis, D. Soft chancre
A: Lymphogranuloma venerum
Answer: A: Lymphogranuloma venerum 
Explanation: Lymphogranuloma venerum