This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: S.T.D., Subject name: Skin
[{'content': 'Soft sore is caused by? \nSelect and explain. \nA. H ducreyi, B. Calymmatobacteriumgranulomatis, C. Chlamydia trachomitis, D. T. Pallidum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is "a\' i.e., H ducrevi o Lesion of primary syphilis-Chancre (Hard - chancre).o Lesion of H. Ducreyi-Chancroid (Soft - chancre).', 'role': 'assistant'}]