Which statement about SF6 circuit breakers is true?

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SF6 circuit breakers use sulfur hexafluoride gas as the insulating and arc-quenching medium. In these breakers, the interrupter chamber is filled with SF6, and when the contacts separate to interrupt current, the arc forms inside the gas. The SF6 gas has very high dielectric strength and efficiently absorbs energy from the arc, cooling it and helping to quench the arc quickly. This lets the breaker interrupt high voltages with relatively small gaps and compact hardware, which is why SF6 breakers are common in many high-voltage applications.

This is distinct from oil-filled breakers (which use mineral oil for arc quenching), vacuum breakers (which rely on a vacuum in the interrupter to extinguish the arc), and air breakers (which use air as the dielectric). While SF6 offers excellent performance, it is a potent greenhouse gas, so modern practice emphasizes careful containment and recycling of the gas.