Scenario While Working with Cultured Mouse Cells, a Researcher Unknowingly Treated

Multiple Choice

Scenario
While working with cultured mouse cells, a researcher unknowingly treated the cells with a mutagen that causes the deletion or insertion of individual nucleotides in DNA. Subsequently, the researcher isolated and cultured a single cell from this group and noticed that the progeny of this cell were not producing a certain protein, and that this affected their survival.
-The mutation would be most harmful to the cells if it resulted in ________.

A) a single nucleotide insertion near the start of the coding sequence
B) a single nucleotide deletion near the end of the coding sequence
C) a single nucleotide change in the middle of an intron
D) deletion of a triplet near the middle of the gene