Which of the following is not an authoritarian form of government
a. absolute monarchy
b. dictatorship
c. direct democracy
d. totalitarianism

Authoritarian governments are where there is a group, or one person, who makes every decision and basically has complete control. So the answer is C) Direct democracy because people have power also. We are able to vote.

C. However, as we've seen in places like Gaza? Direct democracy can and often does lead to authoritarian rule. A matter of IF the people are willing to accept the moral decency and self control that goes with having direct democracy. Something even our founders knew to avoid at all costs. which is why we have a 3 branches of equal power (2 elected) republic. 

Napoleon was voted into his office as the Savior of the Republic. Then promptly crowned himself Emperor. To cheers and loud acclaim.