no because black holes can only form through supernovas.
Black holes
Supernova happens when a star that is at least 3 times larger than our sun dies, it will be crush by its own gravity. Then boom, supernova. Then the star acts like a sponge, it will get bigger. That star is not a star anymore, it is a black hole.
No, only small ones, the supermassive ones are at the centre of galaxies.
A supernova can become a neutron star, or a black hole. Whether it becomes one or the other depends on the mass that remains after the supernova explosion (remember, part of the matter is blown into space). The more massive objects become black holes. As to the "why", this is because after a certain mass limit, there is no known force that can stop gravity.
Whatever they were, they probably died as supernovas and ended up as black holes over 12 billion years ago. Maybe they were the seeds of the central black holes in some current galaxies.
Joan Marie Galat has written: 'Black holes and supernovas' -- subject(s): Black holes (Astronomy), Juvenile literature, Supernovae 'Best of Alberta' -- subject(s): Guidebooks, Guides
B and D
The black holes from Gamma ray usually burst because of their energetic form.
Probably stellar mass black holes
In an indirect way, yes. Gama rays are the highest-intensity form of electromagnetic energy. They usually indicate a very power energy source. Most black holes are formed by exploding stars called supernovas. These events can be detected as gamma ray bursts.
Black holes are sort of the final stage of stellar evolution; they don't form much else. Two black holes may merge to form a larger one, and after a very, very long time, they will evaporate.