Final answer:
The relationship that is NOT adversarial is fiduciary.
Step-by-step explanation:
Adversarial relationships refer to interactions or connections between parties that are characterized by conflict, opposition, or hostility. In various contexts, adversarial relationships can arise due to differences in interests, goals, values, or beliefs.
The relationship that is NOT adversarial is fiduciary. An adversarial relationship is a relationship where two parties have opposing interests and are in conflict. The other options - arm's length, buyer beware, and caveat emptor - all represent relationships where there is a level of opposition or potential for conflict between the parties involved.