Answer: D) Everyone who isn't going on the field trip with the rest of the band ensemble need to get out a pencil and paper to do a timed, in-class essay.
Explanation: Subject verb agreement means the subject and verb must have the same number (both singular or both plural). . The indefinite pronouns anyone, everyone, someone, no one, nobody are always singular and, therefore, require singular verbs. From the given options, the one that has the subject-verb agreement error is option D, because the subject is "everyone" (which is singular) and it says "need" which is a plural verb, the correct sentence would be: Everyone who isn't going on the field trip with the rest of the band ensemble needs to get out a pencil and paper to do a timed, in-class essay.