Answer:
They are variants
Explanation:
The biological concept of species states that members of the same species can reproduce they have a genetic reservoir in common: many genetic variants.
Genetic variability is the measure of a species organism´s tendency to differentiate. In genetic variability, individuals of the same species are not identical. They are recognizable as members of the same species, but they differ in shape, function, and behavior. There exist variations among individuals of the same species.
Genetic variability originates from mutations, recombinations, and karyotype alterations. It allows or makes possible evolution.
Groups A and B can be considered variations of the same species. They not only overlap but also share most of the genetic sequences with only a few nucleotide differences.
These variations might be the previous step for sympatric speciation.