The X-ray diffraction analysis by Rosalind Franklin and Maurice Wilkins demonstrated that:

• A. the nitrogenous bases of DNA were held together by hydrogen bonds.
• B. the structure of DNA was some sort of helix.
• C. the structure of DNA is composed of nucleotides.
• D. the number of purines is equal to the number of pyrimidines in a DNA molecule.

Answer: (B)