Final answer:
The Milky Way is a spiral galaxy featuring a supermassive black hole at its center that is 4 million times the mass of the sun.
Step-by-step explanation:
The Milky Way galaxy is an example of a spiral galaxy. At the center of this galaxy lies a massive black hole that is approximately 4 million times the mass of the sun, exerting a huge gravitational pull. Therefore, the correct answer to the question is B) spiral, black hole. Spiral galaxies, such as the Milky Way, contain both old and young stars along with interstellar matter. The core of our Galaxy, in particular, has a supermassive black hole, a phenomenon supported by strong observational evidence despite the inability to observe black holes directly due to their nature of not emitting light.