Which of the following formula indicates 'Chargaff's rule'?

Always the two strands of DNA are complementary to each other. So, the adenine of one strand will pair with thymine of the opposite strand, while guanine will pair with cytosine. The base pairing (A with T; G with C) is called Chargaff's rule, which states that the number of purins is equal to the number of pyrimidines. In other words, the amount of 'A' base found in the DNA of a cell equals 'T', and the amount of 'C' found in a cell equals the amount of 'G'. Ref: Textbook of Biochemistry for Medical Students By Dm Vasudevan, 2011, Page 470.