Concerning Dark Energy, We Do Know

Multiple Choice

Concerning dark energy, we do know:

A) that it is created when matter annihilates anti-matter.
B) its density remains constant over time, so it is not important in the early Universe.
C) combined with dark matter, it will ultimately produce a closed universe.
D) that it was revealed with Type II supernovae distances in the late 1990s.
E) that it makes up 90% of all the matter and energy in the whole universe.