N early Christian art, mosaics were a popular art form that used small, colored pieces of glass or stone. Which statement best describes most of the early Christian mosaics?

The correct answer is
Mosaics picture stories from the Bible

These types of mosaics were found as early as the 4th century AD and mostly showed pictures from the Bible. Saints and kings started getting shown a bit later, but soon after the earliest ones. These can be found in basilicas and churches like those in Ravenna.