Biology

The correct answer is: B.Chromosome condensation

During the S phase (Synthesis phase) of the cell cycle, the main event is DNA replication, where each chromosome is duplicated to form two sister chromatids. The centromere also replicates during the S phase to ensure proper attachment of the chromatids when they eventually separate.

However, chromosome condensation does not occur in the S phase. Chromosome condensation begins in prophase, which is part of mitosis (M phase), and is important for the p...