The correct answer is D) Residents vote to establish them based on local needs.
Special districts are local governments that are created by a local community because of a special need. As the answer shows, to create one special district residents of that area should vote on the creation because of that special need that makes this place different from others. The form of government of this districts is an independent board of directors that are elected for a fixed term.
The Mongol empire seemed to last a short time due to the fact that they were united only for a common goal, was further destabilized by plague & revolts from conquered countries.
