What should be done to eliminate this issue going forward?

A developer used custom settings to store some configuration data that changes occasionally. However, tests are now failing in some of the sandboxes that were recently refreshed.

What should be done to eliminate this issue going forward?
A . Set the setting type on the custom setting to List.
B. Replace custom settings with custom metadata.
C. Set the setting type on the custom setting to Hierarchy.
D. Replace custom settings with static resources.

Answer: B