Which is currently the most supported theory about the future of the universe

these are the choices
1.The universe could remain exactly as it is today.
2.The universe may continue to expand.
3.Stars could burn out, causing the universe to become dark and cold.
4.Gravity could pull galaxies back together, causing a reverse of the big bang.

2.The universe may continue to expand.                  

Explanation:

Currently, the most supported theory about the future of the universe is that the universe may continue to expand and as it expands, it will experience a reduction in temperature until the universe becomes too cold to support life. This is known as the Big Chill theory. This theory is an opposite of the big crunch theory which asserts that instead of the universe to expand, it will recollapse as a result of increasing gravity.