Which of the following is key event of anaphase of mitotic division?

Chromosomes are moved to spindle equator and get aligned through spindle fibres to both poles in metaphase of mitotic cell division. Chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements in telophase of mitotic cell division. During anaphase, the centromere of each chromosome divides and two chromatids separate completely to become daughter chromosomes. The daughter chromosomes move towards the opposite poles.