$i. \;RNA\; polymerase \;I \;transcribes \;rRNAs$.
$ii. \;RNA \;polymerase \;II \;transcribes \;snRNAs.$
$iii. \;RNA \;polymerase \;III \;transcribes \;hnRNA.$
$iv. \;RNA \;polymerase \;II \;transcribes \;hnRNAs.$
$i.$ 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.