This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sexually transmitted diseases, Subject name: Dental
[{'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. Treponema Pallidum, B. Treponema Peunae, C. Chalmydia Trachomatis, D. Chalmydia Trachomatis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Syphilis causes genital ulcers and cutaneous lesion of any morphology( macular, papular, papulosquamous, nodular ) but is never vehicular or Bullous. Causative agent of syphilis is Treponema pallidum. From illustrated synopsis of dermatology and sexually transmitted diseases neena khanna 5th edition page no 320', 'role': 'assistant'}]