The correct answer is B. Fragment: contains no predicate
Step-by-step explanation:
For a sentence to be complete rather than just a fragment you need two elements: the subject and the predicate. The subjects refer to the person or agent that is being described or that carries out the action, while the predicate contains the verb and other elements such as objects that complete the meaning.
The sentence presented "On December 17, 1903, at Kitty Hawk, the Wright Brothers" introduces the subject "the Wright brothers" and the context of the sentence "On December 17, 1903, at Kitty Hawk"; however, there is no verb such as were, invented, went, etc. that can complete the idea or what were the Wright brothers doings or what happened to them and thus the sentence is a fragment because there is not a predicate.