Final answer:
There are three fundamentally different types of black holes expected to exist: atomic-mass black holes, stellar-mass black holes, and supermassive black holes, differentiated by their mass, spin, and electrical charge.
Step-by-step explanation:
Black holes are classified based on distinct properties they can possess. According to theoretical physics, there are three fundamentally different types of black holes in terms of the properties they can reveal about themselves: their mass, their spin (rotation), and whether they have any electrical charge. Therefore, the answer to the question of how many fundamentally different types of black holes are expected to exist is (C) three—atomic-mass black holes, stellar-mass black holes, and supermassive black holes. These types are differentiated by their formation process and mass scale, with atomic-mass black holes being hypothetical ones that may have been created in the Big Bang, stellar-mass black holes formed by the supernova collapse of massive stars, and supermassive black holes found at the centers of galaxies and holding massive amounts of mass.