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
In translation process, proof reading of mRNA is done by: 
Select and explain. 
A. RNA polymerase, B. Aminoacyl tRNA synthetase, C. Leucine zipper, D. DNA
B: Aminoacyl tRNA synthetase
Answer: B: Aminoacyl tRNA synthetase 
Explanation: Amino acyl tRNA synthetase which recognises the specific tRNA is a proof reading mechanism.
Reference- Harper 30th edition Pg- 415