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
Which of the following antibiotic structurally resembles aminoacyl tRNA and also inhibits protein synthesis: 
Select and explain. 
A. Puromycin., B. Tetracycline., C. Chloramphenicol., D. Sulphonamides.
A: Puromycin.
Answer: A: Puromycin. 
Explanation: Puromycin structurally resembles aminoacyl t-RNA and inhibits protein synthesis by causing premature termination. Tetracyclines inhibit the binding of aminoacyl-tRNA to the A site.