Which led most directly to the Roman Republic's demise and its transition to an empire?

A. slave revolts

B. the failure of direct democracy

C. consuls staying in power too long

D. war with the Etruscans

The answer to your question is C. Consuls stayed in power for too long causing the economy to crash leading to the Roman Republic's demise.

The correct answer is C) the failure of direct democracy.

The element that most directly led the Roman's Republic demise and its transition to an empire was the failure of direct democracy.

During the first part of Ancient Rome (509 BC - 27 BC), the people were ruled by elected officials. That was some kind of democracy as we understand it today. But things began to change, people showed less interest in government issues, and the failure of direct democracy led to the formation of an Empire, where only one man was the leader. The period of the Roman Empire was 27 BC to 476 AD.

Another important element in the ending of the Roman Republic was the alliance between Julius Cesar, Marcus Licinius Crassus, and Pompey The Great. This alliance was called the First Triumvirate.