When a central government has essentially all important powers, the system is termed balance of power.
federalism.
a unitary system.
confederalism.

Option: A unitary system.

Explanation:

A unitary state is a governing system in which a central government holds total power over all other political subdivisions. The central government controls weaker states, and the control not shared between states. Some of the nations who follow a unitary system are France and the United Kingdom.

i beleive a. is the only possible answer

fourteenth amendment