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
[{'content': "Frei's test is diagnostic of: \nSelect and explain. \nA. Lymphogranuloma venerum, B. Lymphogranuloma inguinale, C. Donovanosis, D. Soft chancre", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lymphogranuloma venerum', 'role': 'assistant'}]