Unlike "indigenous peoples," what term, which highlights the prominence that the exclusion of strangers has assumed in day-to-day politics worldwide, has been claimed by majority groups in europe?

The correct answer is "autochthon." 
The word "autochthon" comes from the prefix "autos-," which means "self," and the suffix "-khthon," which signifies "earth" or "soil." In ancient Greek, it literally means "sprung from the earth." This word is currently used for indigenous peoples, because it indicates that these people are original to the location in question.

Sector is best defined as (part).