Will give brainliest if best answer!

which of the following is a basic building block of galaxies?

a. stars

b. gas

c. dust

d. all of the above

Stars are the basic building blocks of galaxies.

Explanation:

Stars are the dense embedded structures formed in compact in clusters. They range from  a dozen to million of stars.These are he observational indicators  of the gas expulsion from clusters  which may occur even quicker or late than  a stellar crossing time scale or within. They are classified into two main groups: OCs and globular clusters

OCs: They are ranging from few tens of millions of years old.They are generally young objects. They are  less tightly bounded by the gravity. & less densely populated.

Globular Clusters: These are a tight compositions/ formation of old stars which are distributed roughly in the galactic halo spherically  i.e.around the galactic center. Around the galactic centers they are having a  high elliptical orbits.

d

explanation:

c is the correct answer hope this !