This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Skin
[{'content': 'Painful ulcer on glans penis is seen in: \nSelect and explain. \nA. Syphilis, B. Lymphogranuloma venerum, C. Chancroid, D. Chancre', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans: (c) ChancroidRef: Harrison 19th ed. / 881, 1134* Chancroid is a bacterial STD caused by H.Ducreyi. It is characterized by painful sores on the genitalia. Chancroid is known to spread from one individual to another solely throueh sexual contact.* A chancre on the other hand is a painless ulceration/ sore most commonly formed during the primary stage of syphilis.', 'role': 'assistant'}]