Final answer:
Building flexibility into a system that allows different customers to create their own use environment during their interactions with the service refers to option 1: Mutable.
Step-by-step explanation:
Building flexibility into a system that allows different customers to create their own use environment during their interactions with the service refers to option 1: Mutable.
This means that the system can be changed or adapted to meet the needs and preferences of individual customers. For example, a website that allows users to customize their profile or settings would have a mutable system.