Answer:
Its a substitution mutation because one of the specific base, G is replaced by A.
This is a Point Mutation because Point mutation brings changes in the structure of a gene because of the substitutions with another base pair. Like in this case, G is substituted by A. In case of frameshift mutations, there is a change in the number of nucleotides due to either insertions or deletions of the nucleotides, which is not in this case.