Answer:
D. Language has a structure that is governed by rules
Step-by-step explanation:
Human language is based on structure which is a set of rules. In normal statement like structure, subject, verb and object, is formal sentence rule. In this sentence, Yoda object in the beginning, instead of the end, and hence he makes a mistake. His sentence should run like "You will be afraid", instead of what it is. A speaker commits an error if he does not follow the rules of a language structure.