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: Biochemistry
Fidelity of protein translation depends on: 
Select and explain. 
A. RNA polymerase, B. DNA polymerase, C. MRNA polymerase, D. Amino acyl t-RNA synthetase
D: Amino acyl t-RNA synthetase
Answer: D: Amino acyl t-RNA synthetase 
Explanation: D i.e. Amino acyl t-RNA synthetase