Final answer:
The activation of both MPF and MAPK results in mitotic spindle formation during the M-phase, which is crucial for chromosome segregation and subsequent cell division.
Step-by-step explanation:
The activation of both MPF (maturation-promoting factor) and MAPK (mitogen-activated protein kinase) results in mitotic spindle formation of the cytoplasm during M-phase. This process is essential for the proper segregation of chromosomes into daughter cells during mitosis. MPF plays a critical role in the M checkpoint of the cell cycle, ensuring that the cell's genetic material is correctly condensed and that the mitotic spindle apparatus is in place. The spindle fibers, composed of microtubules, not only help separate the sister chromatids by exerting tension on the kinetochores but also contribute to the physical division of the cell cytoplasm during cytokinesis. Hence, the correct answer to the student's question is D) Mitotic spindle formation.