From this pie chart we can see that there is only one religion that dominates Northern Africa, while all other religions have very few followers. This religion is the Islam. Northern Africa is dominated by the Islam, more specifically by the Sunni Islam. While there were lot of Christians, Jews, and traditional African religions in the region in the past, over time, the Muslims persecuted them, forced them to convert, or they migrated because of safety reasons, so nowadays they have very small number of people practicing them.
Naturalization is the process of becoming a citizen of a country where you don't come from. After you naturalize, you get the rights and responsibilities of being that country's citizen.