We know that dna and rna (each with four nucleotide components) both use a three nucleotide genetic code and 64 codons (43 = 64). knowing that the minimum number of codons for the genetic code is 21 (20 amino acids, 1 stop codon), what codon size would be required if only three nucleotides were present in the genome?

a) 2 nucleotides per codon
b) 3 nucleotides per codon
c) 5 nucleotides per codon
d) 4 nucleotides per codon
e) 6 nucleotides per codon