The correct answer is - urbanization.
The process of urbanization is the one associated with the growth and development of the cities. This process takes place when there's a growing population in a city, both caused by fertility rates and migration towards it, so the local authorities are making the peripheries of the cities and surrounding villages modernized and start to put institutions in them, as well as the necessary modern infrastructure.
Wouldnt in just be 1 and 3 culturally
The Inca empire was based in Peru. Note that the empire spread in more countries then just the seat of the empire, like Ecuador, Bolivia, Colombia, Chile and Argentina.
Sub-Saharan Africa<span> is, geographically, the area of the continent of </span>Africa<span> that lies south of the </span>Sahara<span> Desert. Politically, it consists of all </span>African<span> countries that are fully or partially located south of the </span>Sahara<span> (excluding Sudan, even though Sudan sits in the Eastern portion of the </span>Sahara<span> desert).</span>