Which was true about the Roman Senate?

A senate was a large building which employed tax collectors, it grew from Romulus' 100 elders on the advisory board, to be the main source of governance in ancient Rome.

Senators (upper class Romans) worked there, controlling finances, foreign policies and war; they also controlled legislation.

Julius Caesar's acceptance of Dictatorship worked to get establishment of an Emperor.

The senate carried on existing, and republican sentiment lived on, it was subordinate unto the Emperor's will.

It was housed in the Curia Hostilia until it burnt down, then it was rebuilt as the Curia Julia after Julius Caesar.

(Information from Caesar III)