The step where nondisjunction can occur in eukaryotic cell division is b Anaphase in mitosis.
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division. In mitosis, this can occur specifically during anaphase, leading to daughter cells with abnormal chromosome numbers. While nondisjunction can also happen in meiosis (specifically in anaphase I or anaphase II), the question specifies eukaryotic cell division generally, and mitosis is often the division referred to in that context.