According to Current Understanding, Which of the Following Is Required

Multiple Choice

According to current understanding, which of the following is required in order for a planet to have rings?

A) The planet must be at least as massive as Saturn.
B) The planet must once have had a large moon that came too close to it, shattering the moon and creating the ring particles.
C) The planet must orbit its star at a distance greater than Mars orbits the Sun.
D) The planet must have many small moons that orbit relatively close to the planet in its equatorial plane.