Which characteristic is true about Saturn's rings?

The characteristic that is true about Saturn's rings is that they have distinct gaps known as the Cassini Division. This division is a prominent gap located between the A and B rings of Saturn and serves as one of the more notable features of the ring system. The Cassini Division is caused by the gravitational influences of Saturn’s moons, which affect the particles in the rings, creating areas of lower density where fewer particles are present.

Understanding the structure of Saturn's rings provides insight into not only the dynamics of ring formation and composition but also the interactions between celestial bodies. For example, the presence of gaps like the Cassini Division showcases how the orbits of nearby moons can shape the ring system by gravitational interactions.

In contrast, the other options describe characteristics that are not applicable to Saturn's rings. They aren’t made of liquid metal or entirely of rock fragments; instead, they consist mainly of ice particles, with some rock and dust mixed in. Additionally, the rings do not rotate slower than Saturn itself; they actually share the same rotational period but may have varying speeds of individual particles depending on their distance from the planet.