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
Chloramphenicol act through action on : 
Select and explain. 
A. 50S ribosome, B. 30S ribosome, C. Nucleus, D. Mitochondria
A: 50S ribosome
Answer: A: 50S ribosome 
Explanation: None