Answer:
Importer.
Explanation:
An importer is an individual or entity that brings in products from foreign countries for sale domestically. Importers buy products that are produced in other countries. To the other country this is an export.
Roberto's father and uncle started a company that buys bauxite, copper, and other minerals from Chile, and brings them into the U.S. So the company is involved in importing activity.
Roberto brokers the trades with the mines in Chile.
