Which lines from "the inchcape rock" best support the inference that the bell the abbot put on the rock saves lives?

"the buoy of the inchcape bell was seen, a darker spot on the ocean green; "

"so little they rose, so little they fell, they did not move the inchcape bell."

"on a buoy in the storm it floated and swung, and over the waves its warning rung."

"when the rock was hid by the surges’ swell, the mariners heard the warning bell; "