Answer:
The correct option is B: requiring turtle-excluder devices on shrimp nets is protecting
Explanation:
Option A is wrong because the verb does not comply with the singular subject, which in this case is "compliance", and hence the "protect" should be "protects"
Option B is the correct answer because "require" was used with a direct object and the singular verb "is" was also correctly used in the sentence and it agrees with the singular subject "compliance".
Option C is wrong because the word "protect" as used in the sentence is a plural verb and hence it does not comply with the singular subject "compliance"
Option D is wrong because the word "are" is a plural verb and hence it does not comply with the singular subject in the sentence, which is "compliance".
Option E is wrong because the usage of "to require" is unidiomatic