Final answer:
The reformation of the nucleolus, Golgi complex, and ER occurs during telophase, the final stage of mitosis.
Step-by-step explanation:
The reformation of the nucleolus, Golgi complex, and endoplasmic reticulum (ER) occurs during telophase, which is the final stage of mitosis before cytokinesis. During this stage, the previously fragmented and dispersed membranous organelles reassemble and the nucleolus reappears within the newly formed daughter nuclei. In contrast, during prophase, these structures break down to allow the chromosomal material to be accessed and segregated correctly during cell division. In metaphase, chromosomes line up at the metaphase plate, and anaphase involves the separation of sister chromatids.