This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'Growth on a cell-free aificial solid medium is possible for following except - \nSelect and explain. \nA. Ureaplasma urealyticum, B. Mycoplasma Pneumoniae, C. C & L form of proteus vulgaris, D. Chlamydia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: They are bacteria but may be considered as viruses on account of their filterability and failure to grow in cell-free culture media. REF: Textbook of microbiology Ananthanarayan, and Paniker. Page no.: 415', 'role': 'assistant'}]