Which of the following is/are responsible for giving a galaxy its particular shape?

a. dark matter
b. supermassive black holes
c. dust and gas
d. cosmic microwave background radiation

The "dark matter" is responsible for giving a "galaxy its particular shape".

Explanation:

In a galaxy, it is mainly the dark matter that holds the galaxy together. A galaxy that is in motion exerts centrifugal force on the planets, stars and other material. This force tends the planets and stars to move away from the "center of the galaxy". On the other hand, the dark matter deploys gravitational force on the material present in the galaxy which holds it in its place.

The enviroment with hedge hogs

Answer primary waves;