Final answer:
An inhibitor prevents the Cdk from activation, thus acting as a control mechanism to ensure proper cell cycle progression and prevent premature or erroneous cell division.
Step-by-step explanation:
The question is asking about the role of an inhibitor in the function of Cyclin-dependent kinases (Cdks). An inhibitor prevents the Cdk from activation. This is because Cdks, which are crucial in regulating the cell cycle, need to be fully active to progress the cell cycle. Cdk inhibitors will bind to the Cdk and prevent it from becoming active until certain cell cycle events are completed, thus acting as a quality control mechanism. This ensures that cells do not divide with errors, which can be critical for preventing diseases such as cancer.