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': 'Drug of choice in pseudomonas septicemia is - \nSelect and explain. \nA. Methicillin, B. Cellazidime, C. Moxalatum, D. Piperacillin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]