Which son of Philip V took the throne and started the 3rd Macedonian War after Philip's defeat at Cynoscephalae?

The correct choice is Perseus, who was the son of Philip V of Macedon. After Philip's defeat at the Battle of Cynoscephalae in 197 BCE during the Second Macedonian War, Perseus ascended to the throne and faced the challenges of consolidating his rule and confronting the Roman Republic. His reign marked the beginning of the Third Macedonian War, which was characterized by ongoing conflicts between the Macedonian kingdom and the Romans as they sought to expand their influence in the region. Perseus aimed to revive the power of Macedonia and resisted Roman dominance, illustrating the tensions that persisted in the face of previous defeats. Understanding the context of his reign provides insight into the shifts in power dynamics in the Hellenistic world following Philip V's earlier rule.