When ceaser augustus came to power, this form of government disappeared from rome.

It was the Republic. 

The senators failed to gain the support of the Roman people of killing Julius Caesar and a power struggle took place where all the armies of the Republic were defeated by Mark Anthony, Octavian and Lepidus at the Battle of Philippi in 42 B.C. Later Anthony and Octavian fought at Actium where Anthony and Cleopatra were defeated and took their own lives.  Octavian’s victory marked the end of the Republic and the start of the Empire of Rome where he was give the name Augustus.

what are the choices? the multiple choices?

i will answer in the comments after the choices have been said.

try something like republic or democracy joined or something because its talking about a election party.