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
Which of the following is not a post transcriptional modification of RNA? 
Select and explain. 
A. Splicing, B. 5' capping, C. 3' polyadenylation, D. Glycosylation
D: Glycosylation
Answer: D: Glycosylation 
Explanation: None