The correct answer is B. Separation of sister chromatids and centromeres.
During metaphase of mitosis, there is alignment of chromosomes at the equatorial plate of the cell and then Anaphase begins with separation of the duplicated centromeres of each pair of sister chromatids. The daughter chromosomes starts moving toward opposite poles due to the action of the spindle fibres. As this stage chromosomes appear like V or J shape. At the end of anaphase, a complete set of chromosomes has gathered at each pole of the cell.
