What type of galaxy has stars that are arranged in a disk with arms that surround a central bulge?
I would say a Spiral Galaxy.
I think like this one:
[This picture of the nearby galaxy NGC 3521 was taken using the FORS1 instrument on the European Southern Observatory's Very Large Telescope at the Paranal Observatory in Chile. The large spiral galaxy lies in the constellation of Leo (The Lion), and is only 35 million light-years away.
Credit: ESO/O. Maliy]