Mitosis is a way for a cell to replicates its chromosomes thereby producing two identical nuclei for cell division. It follows different phases during the cell division.
When the chromosomes begin to move towards the opposite poles, it is in anaphase. Each chromosome's sister chromatids separate and move to opposite poles of the cell. This is the fourth phase of Mitosis. The duplicated genetic material that is carried in the nucleus to two identical daughter cells are being separated in this phase.
Prophase is the first phase of Mitosis. Telophase is the part where the chromosomes already arrived at the cell poles. It is the fifth and final phase of Mitosis.
Answer - B. telophase