The correct answer is: Promoter
Promoter is a sequence on DNA molecule that initiates transcription of a particular gene (RNA polymerase binds to a promoter).
mRNA is a product of transcription from DNA and it has
5′ untranslated region-
Protein-coding region- composed of codons that caries the information for protein synthesis (translation).
Start (the first codon, usually AUG triplet) and stop codons (the last codon for the termination of translation)
3′ untranslated region-after the start codon, usually responsible for mRNA stability and localization.