Question

The picture below shows two galaxies:

Which of these statements best describes a similarity between the two galaxies?

a. Both have elongated centers.
b. Both have centers shaped like bars.
c. Both change their shape from time to time.
d. Both are held together by gravitational forces.

Answer 1

I guess that they're held together by gravitational forces.
But not sure, you should ask this in the physics section.