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
True regarding aminoacyl t-RNA synthetase is A/E 
Select and explain. 
A. lsoaccepting t RNA, B. Implement genetic code, C. Attachment of amino group to 5' end, D. Editing function
C: Attachment of amino group to 5' end
Answer: C: Attachment of amino group to 5' end 
Explanation: C i.e. Attachment of amino group to 5' end