The sunbelt is an example of a region. perceptual functional formal political

I believe the answer is: Perceptual region

Sunbelt refers to the collection of region that perceived to has hotter temperature compared to other states.

Perceptual region refers to the region which characteristic is defined by personal perception that people have for the region.

This could include the perception that based on temperature (such as sunbelt region) , perception based on culture, or perception based on demographic.

answer; standardization;