Answer:
This questionarie includes the following options:
A) The United States uses a system of federalism to govern.
B) The United States employs a republican form of government.
C) The structure of government of the United States is built on separation of powers.
D) The structure of government of the United States protects the civil liberties of its citizens.
and the related excerpts are
from Article I, II & III of The US Constitution, Section 1 each accordingly, as follows:
“All legislative powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.”
“The executive power shall be vested in a President of the United States of America.”
“The judicial power of the United States, shall be vested in one Supreme Court, and in such inferior courts as the Congress may from time to time ordain and establish.”
The most suitable answer would be option B) due the definition of "Republic" according to American constitutional law, is a form of government were the use of power is conditioned by the rule of law and invested on elected individuals representing the citizens, where the separation of powers is included, and where basically the country is a public matter.