Take a look at the passage again:
Lying awake in the dark room, staring up at the shadows that danced across
the ceiling. Jason worried about the shuffling
and thumps that he heard outside. Raccoons—not hungry zombies with
grabbing arms—were prowling behind the house.
You chose the second part, Jason worried about the shuffling and thumps that he heard outside. This part has a main clause: Jason is the subject; worried is the verb. A fragment will not have a main clause.
Go back to the passage to try again.