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 which acts by binding to B site in prokaryotes: 
Select and explain. 
A. Actinomycin-D, B. Chloramphenicol, C. Puramycin, D. Penicillin
B: Chloramphenicol
Answer: B: Chloramphenicol 
Explanation: Chloramphenicol