In the context of semiconservative DNA replication, which structural feature of DNA most directly enables each parental strand to serve as a template for synthesis of a new complementary strand?

• A. Complementary base pairing between the two antiparallel strands held together by hydrogen bonds that can be separated
• B. Covalent bonding between the two strands that permanently stabilizes the double helix
• C. The triple-helix structure of DNA that provides three templates for copying
• D. The presence of uracil in DNA allowing flexible pairing during replication

Answer: (A)