A. Spiral, Black Hole
The Milky Way galaxy is an example of a spiral galaxy. This is characterized by a disk with spiral arms, a central bulge, and a dark matter halo. The center of the Milky Way galaxy is a galactic bulge that is around 20,000 light years long.
In the very center of the galaxy, there is a massive black hole that is 4 million times the mass of the sun and has a huge gravitational pull. This massive object, known as a supermassive black hole, is a key feature of many spiral galaxies and is thought to play an important role in the dynamics and evolution of these galaxies.