Chargaff's rule states that in an organism

• A
  Amounts of all bases are equal
• B
  Amount of adenine $(A)$ is equal to that of thymine $(T)$ and the amount of guanine $(G)$ is equal to that of cytosine $(C)$
• C
  Amount of adenine $(A)$ is equal to that of guanine $(G)$ and the amount of thymine $(T)$ is equal to that of cytosine $(C)$
• D
  Amount of adenine $(A)$ is equal to that of cytosine $(C)$ and the amount of thymine $(T)$ is equal to guanine $(G)$