Take a look at the passage again:
James opened the door of his cluttered refrigerator.
Which caused a pint of blueberries to fall to the floor. The fruit bounced
and rolled everywhere in an explosion of indigo.
You chose the first part, James opened the door of his cluttered refrigerator. This part has a main clause: James is the subject; opened is the verb. A fragment will not have a main clause.
Go back to the passage to try again.