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
All of the following are true regarding cephalosporins, except: 
Select and explain. 
A. Bacteriocidal agents, B. Active against only gram negative, C. Resistant to beta lactamases by Bird generation cephalosporins, D. None of the above
B: Active against only gram negative
Answer: B: Active against only gram negative 
Explanation: Bacteriocidal agents