Final answer:
The correct answer to which structure the activated MPF complex promotes the formation of and causes DNA to condense into during the Gap2/M-phase transition of the cell cycle is Mitotic Spindle, Chromosomes.
Step-by-step explanation:
An important checkpoint regulator at the Gap2/M-phase transition involves the activation of cyclin B and Cdk1 which form MPF (Maturation Promotion Factor). MPF acts as an active complex causing DNA to condense into chromosomes. The correct answer to the question is C) Mitotic Spindle, Chromosomes. This is because the formation of the mitotic spindle is crucial for the successful segregation of chromosomes into daughter cells during mitosis. Additionally, MPF's activity leads to the breakdown of the nuclear envelope and enables spindle fiber formation, thereby allowing the chromosomes to be captured by the mitotic spindle and ensuring that they are correctly attached to the spindle microtubules before moving onto anaphase.