Question

what type of rotary bits can cause a grinder to catch on rough material edges or shift around?
abrasive
burr
backing
kerf

Explanation:

Burr - type rotary bits have cutting edges that can easily catch on rough material edges or cause the grinder to shift around due to their aggressive cutting action. Abrasive bits grind rather than catch. Backing is a support element, not a bit type. Kerf refers to the width of the cut made by a cutting tool, not a bit type.

Answer:

B. burr