Question

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

Explanation:

Burrs on rotary bits can get caught on rough material edges or cause the grinder to shift as they are irregular protrusions. Backing is a support - related component, kerf is a cut - related term, and abrasive is a general type of material for grinding.

Answer:

C. burr