B. Pinochet's dictatorship ended after the dictator lost a democratic vote.
This is considered unique for a dictatorship because it marked a transition of power through a referendum process, contrasting with the more common outcomes of authoritarian regimes, which often end through violent revolutions, coups, or the death of the dictator. In Chile, a plebiscite was held in 1988, and the electorate voted against extending Pinochet’s rule, leading to a return to democracy.