Final answer:
The establishment of the Second Triumvirate was a direct result of the assassination of Julius Caesar, as his supporters formed a political alliance to restore order to Rome.
Step-by-step explanation:
The event that led to the establishment of the Second Triumvirate was a. the assassination of Caesar. After the chaos that followed Caesar's death, three of his supporters, Octavian, Mark Antony, and Lepidus, formed the Second Triumvirate in an attempt to stabilize Rome and assert control. This political alliance was officially recognized by the Roman state in 43 BCE and was marked by the proscription and purging of their enemies and the consolidation of power among its three members.