Answer:
C. glycosylation
Step-by-step explanation:
The maturation-promoting factor (MPF) is a cell cycle checkpoint that stimulates the passage from G2 (prophase) to M phase (metaphase). MPF also determines that DNA replication during the S (synthesis) phase did not produce any mutations. MPF is inactivated by kinase phosphorylation and activated by specific phosphatases capable of dephosphorylating this protein. On the other hand, glycosylation is a posttranslational modification where a carbohydrate (i.e., a glycan) is added to a functional group of another molecule. Many proteins undergo glycosylation, thereby playing a critical role in regulating protein function.