The complementary base pairs in a DNA molecule are stabilized by hydrogen bonds.

Here's a breakdown:

* Adenine (A) pairs with Thymine (T) via two hydrogen bonds.

* Guanine (G) pairs with Cytosine (C) via three hydrogen bonds.

These hydrogen bonds are relatively weak individually, but the collective strength of multiple bonds along the length of the DNA molecule creates a stable double helix structure. This structure is essential for the accurate replication and transcription of genetic information.