Post-transcriptional modification of RNA | Crack AIPGDEE

Which of the following is not a post-transcriptional modification of RNA?
A.   Splicing                              
B. 5'- capping
C.   3'-poly adenylation            
D. Glycosylation

    Glycosylation has not been mentioned as a post-transistional modification of RNA. 5' - capping: Is required both for efficient translation initiation and protection of 5' - end of MRNA from attack by 5'-3' exonucleases. 3' - poly adenylatlon: Added to 3'-end of mRNA molecules in a post transcriptional processing step. This appears to protect the 3'-end of mRNA from 3' - 5' exo-nuclease attack. Splicing (Removal of introns): Introns or intervening sequences that do not code for proteins are removed. This splicing occurs in the nucleus and serves to bring the exons together. After removal of introns the mature mRNA molecules leave the nucleus.