Which statements describe the geographic theme of regions? different types of regions have little or no effect upon each other. climate regions are defined by their average temperature and their political system. physical regions can be formed by mountains and oceans. cultural regions are limited to specific countries. nations that are members of an economic region enjoy fewer tariffs than non-members. regions share one or more common characteristics.

The answer is the regions share one or more common characteristics.

Explanation:

Regions can be described based on natural characteristics. For example, a region could be defined by its climate. The polar region is determined my similar temperatures and levels of precipitation. Those are two characteristics to create one region. You can have mountain regions or rainforest regions that have specific plants and animals to define them as those regions.  Regions can be defined and divided base on humans characteristics through religion, political borders and culture.