Correct option is A
Explanation-
Statement C - "Insertion of an ‘A’ after position 26 changes the primary structure of the protein and results in synthesis of a truncated protein."
Inserting a nucleotide causes a frameshift mutation. After position 26, the reading frame changes — often leading to premature stop codons. This usually results in a truncated, nonfunctional protein.
This is Correct
Incorrect statements-
Statement A - "Insertion of an ‘A’ nucleotide after position +8 increases the length of the transcript by 1 nucleotide and changes the amino acid sequence of the protein being translated."
While frameshift mutations do alter the amino acid sequence, insertion at position +8 happens before the translation start codon (ATG). Since it's upstream of the coding region, it won’t change the translated protein unless it affects translation initiation — which is not indicated here.
Transcript length may increase, but the protein is unlikely to be affected.
Statement B - "Substitution of the ‘T’ at position 22 changes the primary structure of the protein without altering transcript length."
Substitution can change the codon (and thus the amino acid), but position 22 may fall outside or before the coding region, depending on the location of the ATG. From the sequence, ATG (start codon) begins at position ~+31.
Thus, position +22 is still in the 5′ UTR, meaning this substitution won’t affect the protein at all.
Statement D - "Deletion of ‘A’ at position 9 creates the 'STOP' codon that prevents translation of the protein"
Deletion at position 9 (again, before start codon) cannot directly create a stop codon in the translated region. Since it occurs in the 5′ UTR, it won’t influence the reading frame of the coding sequence unless it interferes with translation initiation, which isn't shown here.
Only Statement C is correct
So, correct option is a - C only
