C.It is a frameshift mutation that changes many amino acids.
Explanation:
Due to the triplet nature of gene expression by codons, the insertion of the single Adenine nucleotide will disrupt the reading frame of the gene (frameshift mutation), such that it is no longer evenly divisible by three.
Thus, resulting in a completely different translated protein from the original.
Biologically: Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants
