According to Chargaff, what is the base pairing rule in DNA?

The base pairing rule established by Chargaff states that in DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). This pairing is crucial for the double helical structure of DNA, allowing for the formation of stable bonds between the complementary bases, which ultimately supports the accurate replication and transmission of genetic information during cell division.

Adenine forms two hydrogen bonds with thymine, while cytosine forms three hydrogen bonds with guanine. This specific pairing contributes to the uniform width of the DNA double helix and is essential for the mechanisms of DNA replication and transcription, ensuring that genetic information is passed accurately from one generation to the next.

The other options do not accurately represent the relationships between the nitrogenous bases in DNA, which is why they do not align with Chargaff's findings.