The correct option is D Splitting of centromere
The splitting of centromere does not occur in anaphase I but occurs in anaphase II. Anaphase is the stage of mitosis or meiosis when chromosomes are split and the sister chromatids move to opposite poles of the cell. During Anaphase II, the centromeres are split, and the new daughter chromosomes are pulled toward the poles. They take on a V-shape as they are pulled back. While the chromosomes are drawn to each side of the cell, the non-kinetochore spindle fibers push against each other, in a ratcheting action, that stretches the cell into an oval shape. Thus, the correct answer is option D.