Final answer:
The derivation of the Watson and Crick model of DNA was primarily based on X-ray crystallography data provided by Rosalind Franklin. This technique was instrumental in decoding the double-helix structure of DNA, leading to the iconic structural model established by Watson and Crick.
Step-by-step explanation:
The most significant information for the derivation of the Watson and Crick model of the DNA double helix was derived from a) X-ray crystallography data. Rosalind Franklin utilized X-ray diffraction methods to demonstrate the helical nature of DNA. Meanwhile, James Watson and Francis Crick formulated the double-stranded structural model of DNA, using data that had been obtained from Franklin's work in crystallography. The X-ray crystallography technique was crucial for them to understand the spatial arrangement of the atoms within DNA, which led to the discovery of its iconic double-helix structure. This information, combined with Chargaff's rules regarding the pairing of nucleotides, enabled Watson and Crick to decode the structure of DNA, for which they, along with Maurice Wilkins, were later awarded the Nobel Prize in Medicine.