During DNA replication, which base pairs together?

During DNA replication, specific nitrogenous bases pair up according to complementary base pairing rules. In DNA, adenine (A) pairs with thymine (T) through two hydrogen bonds, and cytosine (C) pairs with guanine (G) through three hydrogen bonds. This pairing ensures that the genetic information is accurately copied during cell division.

The pairing of adenine with thymine and cytosine with guanine is fundamental in maintaining the structure of the DNA double helix and is critical for the accuracy of DNA replication. This is the reason why the correct answer highlights these specific pairs.

Other combinations presented in the options involve bases that do not correctly pair in DNA; for instance, uracil (U) is found in RNA and does not pair with adenine in DNA, while the other pairs have bases that do not correspond to the correct standard in DNA structure. Thus, the correct answer stands out as the most representative of how base pairing works during the replication of DNA.