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: Microbiology
[{'content': 'Tumbling motility is shown by - \nSelect and explain. \nA. Listeria monocytogenes, B. Proteus vulgaris, C. Borrelia, D. Clostridia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Listeria shows characteristic tumbling motility at 25 °C however, it is non motile at 37 °C.', 'role': 'assistant'}]