Which of the Following Is Evidence That the Object Known

Multiple Choice

Which of the following is evidence that the object known as Sagittarius A* is a supermassive black hole?

A) The Milky Way currently has a powerful active nucleus (AGN) .
B) Star orbits imply a large, invisible mass.
C) Gravitational waves from the central region are consistent with a supermassive black hole.
D) A large accretion disk of gas can be resolved in visible light.
E) The event horizon can be viewed through powerful telescopes.