Final answer:
Octavian married Livia, and their children were named Julia and Tiberius. He formed the Second Triumvirate with Mark Antony and Lepidus and later defeated Antony and Cleopatra at the Battle of Actium. The correct option is a.
Step-by-step explanation:
In 37 BC, Octavian married Livia who's children's names were Julia and Tiberius, making the correct answer to this question (a) Livia; Julia and Tiberius. The history of Octavian, who would later be known as Augustus, is closely tied to the political and military turmoils of the late Roman Republic.
Octavian formed the Second Triumvirate with Mark Antony and Lepidus, a formal and legally established partnership that significantly differed from the informal First Triumvirate which was composed of Julius Caesar, Pompey, and Crassus.
Octavian and Mark Antony later become rivals leading to the naval Battle of Actium, where Octavian emerged victorious over Antony and Cleopatra's forces. This victory and subsequent events paved the way for Octavian to restructure the Republic into the Roman Empire, with him as its first emperor. The correct option is a.