The most accurate response regarding what is similar about the economies of all nations, despite their varying resources and environments, is:
They must answer the basic economic questions of what to produce and how to produce it based on available resources.
This reflects the fundamental economic principles that all nations must address, regardless of their specific circumstances. Every economy needs to determine how to allocate resources to meet the needs and wants of its population, taking into consideration what is available and how it can be utilized effectively.