How has American society changed in terms of ethical diversity over the last century?

The correct response highlights that American society has increasingly embraced ethical diversity over the last century. This shift reflects broader movements toward inclusivity, recognition of various cultural perspectives, and the evolution of social norms. Factors contributing to this increase include the civil rights movement, immigration patterns, and a growing awareness of social justice issues.

As more voices from different backgrounds have become part of the national conversation, ethical diversity has come to represent a wider range of beliefs, values, and practices, marking a significant transformation in society's understanding of ethics. This change indicates a movement towards not only acknowledging but also valuing the richness that ethical diversity brings to American life, thereby fostering a more inclusive society.

In contrast to the other choices, which would imply a stagnation, a reduction, or a purely regional variation in ethical diversity, the acknowledgment of an increasing trend highlights a broader, more national evolution toward embracing diverse ethical frameworks.