Of the following government types, which two are the most opposite?
a.
a dictatorship and a democracy
b.
a monarchy and a dictatorship
c.
a monarchy and an aristocracy
d.
a republic and a democracy

The correct answer A.  "a dictatorship and a democracy".

Explanation:

A dictatorship is a type of government that is authoritarian, centered around a single leader or group of leaders and with limited political pluralism. On the other hand, on a democracy  the citizens have power of decision, the leader is elected through a voting process, and there are two or more political parties to chose from. These two types of government are the ones who have the most opposite characteristics.