Amutation within a gene that will insert a premature stop codon in mrna would result in a longer polypeptide chain result in a shortened polypeptide chain change the location at which transcription of the next gene begins have the same effect as deleting a single nucleotide in the gene

Option B, result in a shortened polypeptide chain

Explanation:

Premature stop codon causes mutation which is called as non-sense mutation. In a non-sense mutation, the nonsense codon do not code for any amino acid instead they stop the coding and causes end of protein synthesis. Due to this, proteins are not synthesized to their full length and are also incomplete. These proteins are mostly nonfunctional, inactive and mutated.

Hence, option B is correct