Here's the breakdown of why the answer is that circumpolar constellations at the South Pole never set below the horizon:

* Circumpolar Constellations: These are constellations that appear to circle around a celestial pole (North or South) without ever setting below the horizon.

* The South Pole: Standing at the South Pole, you are directly facing the South Celestial Pole.

Therefore, any constellation that is circumpolar at the South Pole would be orbiting the South Celestial Pole, meaning it would never go below the horizon as seen from the South Pole.

Let me know if you have any other questions!