There is a theory that gravity could have called could pull back galaxies back together causing a reverse big bang which observation makes a theory less likely than the idea that the universe make you continue to expand

I believe the answer is C.

Universe is expanding at an accelerating disk.

Explanation:

As the universe will continue to expand the galaxies are getting far away from each other and all this has started about 5 billion years ago. Thus the universe will accelerate and expand at a much faster rate and this will grow outwards an give the universe a linger life cycle.