Which of the following is NOT a requirement for a complete sentence?

A complete sentence must generally express a complete thought, have a subject, and include a verb. The requirement for an object is not necessary for a sentence to be considered complete. A subject can perform an action without needing to have an object; for instance, in the sentence "She runs," the subject "She" is performing the action of running, and there is no object required for the sentence to convey a complete thought. Thus, including an object is not a requirement for completeness in a sentence.