Answer:
The correct answer would be codon.
Codon refers to the sequence of three consecutive nucleotides (DNA or RNA) which codes for a specific amino acid.
For example, AUG codes for methionine, CCA codes for proline, GUU codes for valine, UGA is a stop codon et cetera.
The nucleotide sequence of the DNA is transcribed into the codon sequence of the mRNA.
The codon sequence of the mRNA codes for the amino acid sequence of the polypeptide chain.
The codon is deciphered with the help of the anti-codon site of the tRNA.