The federal government/principle
The most populated European nations are Russia, Germany, Turkey, and France. Hope this helps! : )
OIL petroleum and other gas
The answer is The Rule of Reason
For Example, a Manufacture company May restrict the supply of a product in different geographic market only to existing Retailers so they can earn a higher profit which lead to them creating a better service to customers.
This policy can increase the demand of the Manufacturer's product