In analyzing the number of different bases in a DNA sample, all of the following are true regarding the base pairing rule except

Erwin Chargaff discovered that in a DNA molecule, the number of purines always equals the number of pyrimidines. Which of the following base pairs correctly represents a purine-pyrimidine pair?

Chargaff’s Rules helped in deducing the double helix structure of DNA. Which statement best summarizes Chargaff’s Rules?