The correct answer is (a) Watson and Crick.
James Watson and Francis Crick were two British scientists who proposed the double helix model of DNA in 1953. Their model was based on X-ray crystallography data that had been collected by Rosalind Franklin and Maurice Wilkins. The double helix model is a three-dimensional structure of DNA that consists of two strands of nucleotides that are twisted around each other. The nucleotides are arranged in pairs, with adenine always pairing with thymine and guanine always pairing with cytosine. The double helix model is a fundamental concept in molecular biology and has been used to explain many aspects of DNA replication, transcription, and translation.
Fisher and Haldoni were two scientists who proposed a model of DNA in 1952. However, their model was incorrect and was not widely accepted. Lamarck and Darwin were two scientists who proposed theories of evolution in the 1800s. However, their theories did not address the structure of DNA. Hugo de Vries was a Dutch botanist who proposed the mutation theory of evolution in the early 1900s. However, his theory did not address the structure of DNA.