One of the reasons commoners became more attentive to religion in the fifteenth century was that they had more available for them?

They had more printed materials

Explanation:

Prior to the invention of the printing press by Johannes Gutenberg in the 15th century, there was limited printed materials on religious subject which are mainly accessible by the wealthy. The availability of printed religious materials garnered the interest of commoners to religion.

answer; they are called (pebbling);

answer; group behavior;