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: Dental
[{'content': 'Donovanosis is caused by – \nSelect and explain. \nA. Calymmatobactor granulomatois, B. T. pertenue, C. Chlamydia trachomatis, D. H. ducreyi', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Donovanosis (granuloma inguinale or granuloma venerum)\xa0is caused by\xa0calymmatobacterium granulomatis.', 'role': 'assistant'}]