On the desk a nail file which is used is used to open letters .is it run on, fragments of sentence

This sentence should be a fragment.

Explanation:

"On the desk a nail file which is used is used to open letters." I'm guessing the  double use of 'is used' is a mistake.

This sentence has a subject but does not include a predicate. What will the nail file be doing? A sentence needs to have both a subject and a predicate to be complete. It is not a run-on since it does not include multiple subjects or predicates.

i think it would be c. or a. i recommend a if it's not a than it's c if it's not c than it's b your welcome : ) sorry if you get it wrong

answer; (b); the abolitionist movement;