Verified Answer :

WorldlyGlass49

The correct answer is that this group of words is a sentence. It is a complete sentence, regardless of its shortness and lack of subject. It is an imperative sentence, not a fragment.

pastaeyelash

Answer:

Sentence

Explanation:

 A sentence is a group of words that contains a subject and a verb  with a complete thought. A sentence can be declarative, imperative, interrogative, or exclamatory. The group of one word 'Sit!' forms a sentence because it contains the verb 'sit' and the subject  'you' is understood. This is an imperative sentence, which has the purpose to give a command. Example: "Go!" , "Stop!"