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': 'First generation cephalosporins are active against? \nSelect and explain. \nA. Gram negative bacteria, B. Gram positive bacteria, C. Anaerobes, D. Dermatophytes', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Gram positive bacteria", 'role': 'assistant'}]