Answer:
The correct answer is:
Domestic policy issues affect areas within U.S. borders, while foreign policy issues affect areas outside U.S. borders.
This is supported by the information in the search results:
"Domestic policy, also known as internal policy, is a type of public policy overseeing administrative decisions that are directly related to all issues and activity within a state's borders. It differs from foreign policy, which refers to the ways a government advances its interests in external politics." [1]
The search results clearly distinguish domestic policy as dealing with issues within a country's borders, while foreign policy deals with issues outside the country's borders. This is the key difference between the two.