The correct option is A
After the fall of the monarchy the Republic was established in Rome (Res publica, that is to say, 'the public thing'), an aristocratic regime led by some forty gens; the patricians, the descendants of the oldest families in Rome held the power. The main institutions of the new regime were the Senate, the magistracies and the elections.
The Senate was one of the pillars of the Republic, being the political organ that demanded responsibilities to the consuls. Originally the Senate was constituted only by patricians, but from the Lex Ovinia of the year 312 a. C., plebeians were allowed to be part of it. The auctoritas of the Senate gave validity to the agreements taken in the popular assemblies. The Senate also resolved cases of interregnum, a situation that occurred when one of the consuls died.
The Magistracy was an original charge of the Republic. The head of the rex or monarch was replaced by two collegiate and temporary magistrates called consuls who could be held responsible for their government duties. Each magistrate could veto the other, which was known as intercessio. Also during the Republic popular assemblies, called Comitia Centuriata, were created.
