Rationale

C is correct: During metaphase, spindle fibers attach to centromeres and pull chromosomes to align along the metaphase plate at the center of the cell. This alignment ensures each daughter cell receives one copy of each chromosome when they separate. A is incorrect: In prophase, chromatin condenses into chromosomes and the nuclear envelope begins to break down, but chromosomes are not yet aligned. B is incorrect: In anaphase, sister chromatids separate and are pulled to opposite poles. D is incorrect: In telophase, nuclear envelopes reform around each set of chromosomes and the cell prepares to divide.

Key concepts