What defines a nation-state?

A nation-state is defined as an independent geopolitical unit that encompasses a group of people who share a common culture and identity. This concept combines the political entity of a state with the cultural and social dimensions of a nation. The key characteristics of a nation-state include a defined geographic territory, a permanent population, and a government that exercises sovereignty over its affairs. The shared culture and identity often include language, religion, shared history, and traditions, which help create a sense of belonging and unity among the people living within its borders. Thus, option A accurately captures the essence of what constitutes a nation-state, highlighting both the political and social aspects that are intrinsic to this type of entity.