The "After Glow" from Some Clock Faces Is Caused by Atoms

The "after glow" from some clock faces is caused by atoms

A) being excited,
B) vibrating at frequencies greater than a million billion times per second,
C) remaining for some time in a state of excitation before de-exciting,
And materials exhibiting this property are called
D) fluorescent.
E) phosphorescent.
F) incandescent.
G) luminescent.