Which Statement About Saturn's Rings Is Not True

Which statement about Saturn's rings is not true?

A) The rings must look much the same today as they did shortly after Saturn formed.
B) The large gap known as the Cassini Division is shaped by an orbital resonance with the moon Mimas, which orbits well outside the rings.
C) Some features of the rings are shaped by small moons that actually orbit within the ring system.
D) The rings are so thin that they essentially disappear from view when seen edge-on.