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': 'A young man presents to the emergency depament with a maculopapular rash 2 weeks after healing of a painless genital ulcer. The most likely etiological agent is \nSelect and explain. \nA. Treponemapallidum, B. Treponemapeunae, C. Chalmydia Trachomatis, D. Calymatobacter granulomatis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Treponema pallidum Development of nonpruritic maculopapular rash (secondary syphilis) two weeks after heeling of painless genital ulcer (primary syphilis) suggest Treponema pailidium as an etiological aget.', 'role': 'assistant'}]