Final answer:
Deadenylation and decapping are key processes in RNA degradation, which involve removing essential structures from the RNA molecule, marking it for destruction. Option D is correct.
Step-by-step explanation:
Deadenylation and decapping are parts of the RNA degradation process. These processes involve the removal of the poly-A tail and the 5' cap from an RNA molecule, which typically marks the RNA for degradation. This is essential for regulating the levels of various RNA molecules within the cell and for removing defective or unneeded RNA transcripts.
Deadenylation is the process by which the polyadenylate tail is progressively shortened, and decapping is the removal of the 5'methylguanosine cap. Once these modifications are removed, the RNA molecule is more susceptible to exonuclease activity, leading to its complete degradation.