Which of These Statements Correctly Describes Cosmologists' Current State of Knowledge

Multiple Choice

Which of these statements correctly describes cosmologists' current state of knowledge about the future expansion of the universe?

A) The amount of matter (both visible and dark) is only 1/3 the amount needed to halt expansion, so the expansion will continue to slow down but will never stop.
B) The amount of matter (both visible and dark) is only 1/3 the amount needed to halt expansion, and there is strong evidence of a previously unknown form of energy that acts to accelerate the expansion.
C) The amount of matter (both visible and dark) is exactly the right amount needed to halt expansion after an infinite amount of time has gone by.
D) The amount of matter (both visible and dark) is 3 times the amount needed to halt expansion, so the expansion will eventually stop and the universe will begin to collapse.