This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Syphilis was first identified by \nSelect and explain. \nA. Fraenkel, B. Nicolaescu, C. Schaudinn and Hoffman, D. Ogston', 'role': 'user'}, {'content': "Answer: C \nExplanation: Treponema pallidum is the causative agent of syphilis, was first discovered by Schaudinn and Hoffmann in the chancers and inguinal lymph nodes of syphilitic patients. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th edition; Pg: 378", 'role': 'assistant'}]