This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'Codon consist of \nSelect and explain. \nA. 3 base pair, B. 2 base pair, C. Two nucleotide, D. 5 base pair', 'role': 'user'}, {'content': 'Answer: A \nExplanation: DNA is a reference for proteins, which are the functional molecules in cells. These are comprised of 20 unique amino acids, and each is coded for by a stretch of DNA known as a codon. Codons are always 3 base-pairs (nucleotides) in length.Ref: Harper&;s Biochemistry; 30th edition', 'role': 'assistant'}]