Answer: Global commodity chain
Explanation:
Global commodity chain refers to a process where firms gather details, Information and transform them to goods that would be sold to consumers. This process connects various production and distribution centres in producing a particular commodity which is now sold at the global market. An example is iPhone that has it's production in both China and America, another example is car companies where most of their engines might be produced by GM motors and other parts from other production centres.
A.The Roman empire relied on physical features as natural barriers.
