Which of the following describes cytokinesis?

Cytokinesis is the process during cell division where the cytoplasm of a parental cell is divided into two daughter cells, effectively creating two separate entities. It occurs following mitosis, the stage where the genetic material is divided. The description of cells splitting and the formation of two daughter cells accurately captures the essence of cytokinesis.

In contrast, processes such as the shortening of spindles, chromosomes moving to opposite poles, and centrosome migration pertain to other phases of cell division, specifically during mitosis. These processes relate to the arrangement and separation of genetic material, which happens before cytokinesis. Therefore, option B correctly identifies cytokinesis as the stage where the actual division into daughter cells occurs.