Answer:

b. S Phase

Explanation:

Throughout interphase, nuclear DNA remains in a semi-condensed chromatin configuration. In the S phase (synthesis phase), DNA replication results in the formation of two identical copies of each chromosome sister chromatids that are firmly attached at the centromere region.

»»Answer««

The synthesis phase of the cell cycle; the portion of interphase during which DNA is copied.

B. S Phase

»»Explanation««

Throughout interphase, nuclear DNA remains in a semi-condensed chromatin configuration. In the S phase (synthesis phase), DNA replication results in the formation of two identical copies of each chromosome—sister chromatids—that are firmly attached at the centromere region.