Final answer:
REI most likely uses psychographic segmentation to target active outdoor enthusiasts, and the concept of people moving to places compatible with their personalities and needs is known as selective migration.
Step-by-step explanation:
The correct option for the market segmentation basis that REI, a retail outdoor outfitter, would most likely use for targeting people who live active outdoor lives is a) Psychographic. Psychographic segmentation involves dividing the market based on lifestyle, interests, and activities, which aligns with REI's focus on individuals who are enthusiastic about the outdoors.
As for the provided concept definition, the term that describes the phenomenon where people move to areas that align with their personalities and needs is a) selective migration.
This concept recognizes that people often choose to live in locations that mirror their personal values, preferences, and lifestyles, indicating their engagement in selective migration. This process plays a significant role in shaping communities and neighborhoods based on the shared characteristics and interests of their residents.