What Is the Purpose of Cell Cycle Checkpoints

What is the purpose of cell cycle checkpoints?

A) to ensure that cell cycle phases proceed only when the cell is ready
B) to prevent the cell from pausing the cell cycle when problems are detected
C) to coordinate movement through the cell cycle among multiple cells
D) to coordinate cell specialization for its role in particular tissues
E) to ensure that cells containing errors in their DNA do not undergo apoptosis