DNA replication doubles copies during interphase, maintained until cell division

Steps:

• DNA replication in S phase of interphase creates two identical copies of each DNA molecule as sister chromatids.
• These two copies persist through G2 phase of interphase and into mitosis.
• In metaphase, replicated chromosomes (two chromatids each) align at the cell equator.
• During cytokinesis, the dividing cell contains both copies until cytoplasm fully separates them into daughter cells.

Why D is correct:

• Per the cell cycle definition, replication in interphase yields two copies per DNA molecule, which the cell retains through metaphase and into cytokinesis before final division.

Why the others are wrong:

• A: Ignores replication in interphase and separation only after metaphase.
• B: Misses that interphase includes S phase replication, starting with two copies.
• C: Incorrectly reduces copies in metaphase, where sister chromatids remain paired.

Final answer: D