Answer:
Prophase
Step-by-step explanation:
The centrioles in animal cells begin to move apart at the prophase stage of the cell cycle.
At the prophase stage, the nuclear membrane of the cell dissolves or breaks down and the genetic materials condense. They become visible under the microscope as chromosomes.
Also during this stage, the centrioles start their movement towards the opposite poles of the cell with the initiation of spindle formation on each.