Question

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

Explanation:

A burr - type rotary bit can catch on rough edges or shift around due to its shape and cutting action. Abrasive bits are for grinding and don't typically catch in this way. Backing is a support element and not a bit type that causes catching. Kerf is related to the width of a cut, not a bit type for catching.

Answer:

C. burr