Ans.
The A site of ribosome shows a binding site on the ribososmes for the charged tRNA molecules. It is the point, where the aminoacyl tRNA (except first aminoacyl tRNA) first enters during the process of translation, with a new amino acid. Then, a peptide bond is made between the amino acids present at P-site and A-site.
Thus, the correct answer is 'option the tRNA first enters the ribosome, bring in a new amino acid.'