In his book "The Republic",  Plato uses the method of engaging in dialogue to explore which concept?

Justice

he correct answer is Option 4 - Justice

In "The Republic", Plato discusses JUSTICE through a long dialogue between Socrates and his young friends, Glaucon and Adeimantus.

All cultures and traditions have grappled with questions of justice although they may have interpreted the concept in different ways. For instance, in ancient Indian society, justice was associated with dharma and maintaining dharma or a just social order, was considered to be a primary duty of kings. In China, Confucius, the famous philosopher argued that kings should maintain justice by punishing wrong doers and rewarding the virtuous. In fourth century B.C. Athens (Greece), Plato discussed issues of justice in his book The Republic. Through a long dialogue between Socrates and his young friends, Glaucon and Adeimantus, Plato examined why we should be concerned about justice. The young people ask Socrates why we should be just.