Answer:
You didn't add what the options are but here's an explanation of fragment sentences to help you.
Step-by-step explanation:
A fragment sentence is an incomplete sentence.
In order for something to be a complete sentence, it must have a subject and a verb.
E.G of complete sentence: The apple rolls down the hill.
rolls is the verb and the apple is the subject
E.G of fragment sentence: Bacon and eggs.
There is a subject (bacon and eggs), but no verb.