I believe it is Religious Beliefs
The great age of conquest had ended a few decades before. Three legions had been destroyed in the Battle of the Teutoburg Forest by rebellious German tribesmen in 9 AD, and the emperor Augustus concluded that the empire was overextended and called a halt to new wars of conquest.
Explanation: this will help you.
All state governments are modeled after the federal government and consist of three branches: executive, legislative, and judicial. The U.S. Constitution mandates that all states uphold a "republican form" of government, although the three-branch structure is not required.
C. The increase in the use of coal as a source of heat and energy
