The increased migration and increased population that the United States saw during (any) era are examples of "<span>c. demographic and environmental changes," since these have to do mainly with population distribution. </span>
A funnel cloud is a rapidly rotating column of air that is not in contact with the ground, a soon to be tornado.
It murdered thousands of innocent people, turned into an illiberal mess of collectivist radicalism disguised as enlightenment, produced a military dictatorship, ended with complete and total military failure, and resulted in the Bourbon Monarchy being restored.