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': 'Donovanosis is caused by: \nSelect and explain. \nA. H. ducreyi, B. T. pertenue, C. Calymmatobacterium granulomatis, D. Chlamydia trachomatis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. c. Calymmatobacterium granulomatisCalymmatobacterium granulomatis is how known as Klebsiella granulomatis (gram negative, red shaped bacterium)', 'role': 'assistant'}]