What is NOT One of the Nucleotide Bases That Make-Up

Question

What is NOT one of the nucleotide bases that make-up double-stranded DNA base pairs?
A) Adenine
B) Proline
C) Thymine
D) Guanine
E) Cytosine

Accepted Answer

Proline is not a nucleotide base; it is an amino acid. Adenine, Thymine, Guanine, and Cytosine are the four nucleotide bases that form the base pairs in the structure of DNA.