The different forms of interbreeding species that live in different geographical regions are called

The correct option is C Allopatric species

In allopatric speciation, a part of the population becomes geographically isolated from the main population. The population becomes entirely separated and finally constitutes a new species. Formation of Darwin's finches that formed separate species in Galapagos Islands is an example of allopatric speciation.

So, the correct answer is 'Allopatric species'.