Observe the following codons and choose the one that is neither present immediately after UTR of 5' end nor prior to UTR of 3' end of mRNA.

UGG is the codon for amino acid tryptophan. It is neither initial codon nor stop codon. The codon AUG can be present as initiating codon after UTR of 5' end. One of the non-sense codons UAA, UAG and UGA is present prior to UTR of the 3' end in the translated region of mRNA.