Question

the bonds that form between complementary bases are called...
covalent bonds
hydrogen bonds
ionic bonds
strong bonds

Explanation:

Complementary bases (e.g., A-T, G-C in DNA) are held together by weak electrostatic attractions called hydrogen bonds, which stabilize the double helix structure. Covalent bonds link nucleotides in a strand, ionic bonds involve charge interactions, and "strong bonds" is a vague term not specific to base pairing.

Answer:

B. hydrogen bonds