Which sentence has a adjective clause

An adjective clause, also called and adjectival or relative clause, will meet three requirements, First, it will contain a subject and verb. Next, it will begin with a relative pronoun, (Who, Whom, Whose, That, or Which) or a relative Adverb (When, Where or Why.)

answer: b. the benefits of mandatory voting in the united states far outweigh the potential drawbacks.

this is because the other choices are biased.

the answer is something i don't know