Concept:Monarchy is the form of government in which a single hereditary ruler, such as a king, holds supreme authority.
Explanation:A government headed by a king is classified as a monarchy.
In a monarchy, the crown is usually passed down through a royal family line.
Presidentialism places an elected president at the head of government, not a king.
Fascism refers to a dictatorial political movement, not rule by a monarch.
Republicanism is based on elected representatives and an elected head of state.
Therefore, the question is directly answered by the definition of monarchy.
Answer:A. Monarchy