Answer:
A. If populations can interbreed, they are considered one species.
Explanation:
The organisms of a species have the ability to interbreed with one another leading to the formation of an offspring. For speciation to occur, the organism have to get diverged and isolated.
In speciation, a hereditary species parts into at least two relative species that are hereditarily not quite the same as each other and can never again interbreed.
In Allopatric speciation, the species gets geographically parted from their parent and evolves accordingly while in sympatric speciation, evolution of species occur when it stays in the same place as their parent.
