Government by a single person

A. Monarchy

B. Autocracy

C. Plutocracy

D. Aristocracy

Answer: Option B

Solution(By Examveda Team)

One word substitute is Autocracy.

Monarchy: a form of government with a monarch at the head.
Autocracy: a system of government by one person with absolute power.
Plutocracy: government by the wealthy.
Aristocracy: a form of government in which power is held by the nobility.