What comprises a codon? A) a complementary section of RNA B) a sequence of three nucleotides C) a random sequence of nitrogen bases D) a section of DNA referred to as a gene

B) a sequence of three nucleotides

Explanation:

A codon is the sequence of three nucleotides that decide that which particular amino acid would be incorporated in the polypeptide chain. Each codon code for a particular amino acid and responsible for the primary structure of proteins.

During translation the transfer RNA have the anticodon on its one side and amino acid bound to it on its other side. It adds the amino acids to growing polypeptide chain by binding to particular codon on messenger RNA.

Example; AUG is the starting codon for every protein and code for methionine in eukaryotes and anticodon for it is UAC.