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: Pharmacology
[{'content': 'Penicillins are NOT effective against \nSelect and explain. \nA. Gram positive cocci, B. Gram negative cocci, C. Gram positive bacilli, D. Gram negative bacilli', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]