Which best describes a clause?
1. a word or group of words that should help to describe or make clear the meaning of the word it modifies
2. a word that modifies a verb, an adjective, or another adverb
3. a group of words that contains a subject and a verb and that is used as part of a sentence
4. a group of words that does not contain a verb or a subject and that acts as a single part of speech