Understand that mitosis is the process of cell division that results in two daughter cells, and it consists of specific stages: prophase, metaphase, anaphase, and telophase.
Recall that interphase is the phase of the cell cycle where the cell grows and DNA is replicated, but it is not part of mitosis itself.
Identify the stages listed in the problem: telophase, prophase, metaphase, and interphase.
Recognize that telophase, prophase, and metaphase are all stages of mitosis, while interphase is not a stage of mitosis but rather a preparatory phase before mitosis begins.
Conclude that the correct answer to the question 'Which is NOT a stage of mitosis?' is interphase.