While Looking Under a Microscope,you See Two Neighboring Daughter Cells

While looking under a microscope,you see two neighboring daughter cells.One of the cells contains three chromosomes,and the other contains five.The parent cell normally contains four chromosomes.What could be the reason for the different number of chromosomes in the cells?

A) The division of sister chromatids of one chromosome did not occur properly during mitosis.
B) The nuclear envelope did not dissolve, so mitosis could not occur at all.
C) Replication of DNA did not occur properly.
D) The division of homologous chromosomes during meiosis II did not occur properly.