The correct order of the phases of a stem cell is:
mitosis, gene expression, differentiation, specialization
However, since the exact combination of four terms and ordering is not listed among your options, the closest approximation based on the provided choices would be:
mitosis, gene expression, differentiation
This sequence implies that the stem cell first undergoes mitosis (cell division), then the relevant genes are expressed, leading to differentiation into specific cell types. After differentiation, cells may further specialize, which isn't explicitly included in your provided options.