The correct answer would be - they can mate or reproduce and produce fertile offspring.
Explanation:
In the biological world, there can be certain species the might have different looking organism due to environmental condition such as weather, geographical change, and many more.
In such a case, The biological species concept help in determining if these organisms belong to the same species or not. According to this concept, different species are separated by pre and post-zygotic barriers and due to this they can not mate, or even if they mate there would be no fertile offspring.
