What makes dark energy "dark"?

Aits unknown nature

Bits completely black color

Cits existence beyond the visible spectrum

Dits inevitable creation of a totally destructive Big Crunch

Nucleosynthesis began when _____ and ended when _____.

Athe Big Bang occurred; the Big Crunch occurred

Bnuclear reactions could first occur; matter had condensed into galaxies and stars

Cthe cosmic microwave background radiation formed; dark energy replaced it as the dominant energy form

Dthe universe had cooled enough for atoms to combine; protons and neutrons were too far apart to form nuclei