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
Drug effective against pseudomonas is : 
Select and explain. 
A. Penicillin G, B. Gentamicin, C. Tetracycline, D. Chloramphenicol
B: Gentamicin
Answer: B: Gentamicin 
Explanation: None