Question

Which type of government system has a central authority that holds all or nearly all of the power? A) an oligopoly B) a confederation C) a local government D) a unitary government

Answer 1

Hello there.

Which type of government system has a central authority that holds all or nearly all of the power? 

"Holds all the power or nearly all"
 
Unitary-forming a single entity

Based off that, 
Answer: unitary government

Answer 2

Unitary government

The Unitary government is a method of administrative arrangement with a primary supreme government which operates the jurisdiction and presents the conclusions for subordinate local authorities. An illustration of a unitary form of government in the United Kingdom superintending England. A substantial majority of the world's countries which is 165 of the 193 UN member republics become a unitary system of government.