Answer:
b. a large elliptical galaxy
Explanation:
In elliptical galaxies the stars are grouped in an elliptical shape, it has a low quantity of gas and dust in comparison to spiral galaxies, and its stars belong to an old population, there is not new stellar formation in it.
The stars orbit in a messy way which made to believe that they form from the merger of galaxies.
They are also really massive (around solar masses).
The most massive and luminous can be found in the center of cluster of galaxies.