Choose the answer that is a true statement. A mercenary was a soldier who was a former slave. The plebeians were upper-class citizens. The Romans' first code of law was established around 450 B.C. The?

The true statement is that the Romans' first code of law was established around 450 B.C. This code, known as the Twelve Tables, was created to provide a clear set of laws for Roman citizens and address legal rights and duties. The other statements are inaccurate, as mercenaries are typically hired soldiers, not necessarily former slaves, and plebeians were actually the lower-class citizens in Roman society.