Why Is It Believed That the Rings of Saturn Could

Why is it believed that the rings of Saturn could not have formed just as the planet itself formed

A) Over time the solar wind should have blown away the particles in the rings.
B) The particles in the rings should fall into the planet in a short period of time.
C) The rings are made of ice particles which would have been vaporized by the heat released as Saturn formed.
D) The outer planets do not have enough mass to hold on to the rings.