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 30 year old male patient has a large, spreading and exuberant ulcer with bright red granulation tissue over the glands penis. There was no lymphadenopathy. The most likely causative organism is; \nSelect and explain. \nA. Treponema pallidum, B. Herpes simplex virus type 1, C. Herpes simplex virus type 2, D. Calymmatobacterium granulomatis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Calymmatobacterium granulomatis', 'role': 'assistant'}]