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: Medicine
[{'content': 'Unipolar flagellate organism that causes pneumonia - \nSelect and explain. \nA. Pseudomonas, B. Mycoplasma, C. Aeromonas, D. Klebsiella pneumonia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. PseudomonasPseudomonas aeruginosa is a Gram-negative, aerobic rod shaped and polar-flagella bacterium with unipolar motility.', 'role': 'assistant'}]