Answer:
3) black hole
Explanation:
In the Milky Way galaxy center is situated Sagittarius A* - a supermassive black hole (A black hole is an area in space so strong that nothing, not even light can escape from it because of the intense gravitational pull.
With a weight corresponding to 4 million suns, this makes Sagittarius A* one of these giants among other supermassive black holes.
Astronomers have been able to confirm their suspicions by studying stars that orbit around our galaxy’s heart: they behave as if influenced by something incredibly heavy and small but very dense – like a black hole.