Question

which is currently the most supported theory about the future of the universe?
the universe could remain exactly as it is today.
the universe may continue to expand.
stars could burn out, causing the universe to become dark and cold.
gravity could pull galaxies back together, causing a reverse of the big bang.

Explanation:

Current scientific evidence, such as the observation of the accelerating expansion of the universe (supported by studies of distant supernovae and cosmic microwave background), indicates that the universe is likely to continue expanding. The other options are less supported: the universe is dynamic and not static (so not remaining exactly as it is), while the "heat - death" (stars burning out) is a more long - term consequence related to expansion, and the "big crunch" (gravity pulling galaxies back) is not supported by the evidence of accelerating expansion.

Answer:

The universe may continue to expand.