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': 'All of the following are true regarding cephalosporins, except: \nSelect and explain. \nA. Bacteriocidal agents, B. Active against only gram negative, C. Resistant to beta lactamases by Bird generation cephalosporins, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Bacteriocidal agents', 'role': 'assistant'}]