Meselson and Stahl demonstrated that DNA replication is a semi-conservative process. Which of the following best explains the definition of "semi-conservative"?

A. The two strands of DNA are separated from each other and serve as the templates for new strand synthesis thus a newly replicated DNA segment will have one parental template strand and one newly synthesized strand.

B. Upon completion of DNA replication the two parental strands are re-united to produce one duplex whereas the two newly synthesized strands are joined together to produce another duplex.

C. After DNA replication the double helix will have stretches in which both strands are newly synthesized. These regions will be interspersed among segments of the double helix are composed primarily of parental template DNA.

D. Parental strands are degraded by nucleases after replication enzymes have generated new DNA strands. Thus the newly replicated chromosomes will only have newly synthesized strands.