Statement $II :$ $'AAA'$ and $'AAG'$ both codons code for the amino acid lysine.
In the light of the above statements, choose the correct answer from the options given below.
$i.$ Six codons do not code for any amino acid.
$ii.$ Codon is read in $mRNA$ in a contiguous fashion.
$iii.$ Three codons function as stop codons.
$iv.$ The initiation codon $AUG$ codes for methionine.