Sentence Correction (SC) | Re: Last week local shrimpers held a news conference to take

If in C, protect was plural (protects). Would it have been correct? The OG answer says that "that require" is wordy and unnecessary, but that part sounds better to me. Again, assuming it didn't have the protect issue.

hi all,
i know this sub-verb agreement question.
But however i fail to understand the how the Subject is compliance here.
My question will sound silly,but please help me identify the main subject and main verb