<span>Watson and Crick determined the base pairing by using the new information to construct a new double-stranded helix model with the nitrogen bases paired A to T and C to G in the center. This base pairing immediately suggested to Crick that one side of the molecule could serve as a template to exactly replicate DNA sequences to pass on genetic information during cell reproduction. This second, successful model was unveiled in February 1951.</span>
I would say A is the correct answer. B and C are definitely wrong, and I think D is talking about genes and not chromosomes.
All of these things would be considered homologous. Please mark Brainliest!!!
