What is the relationship between Starbucks and coffee in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Starbucks currently sources coffee from nine African countries: Ethiopia, Rwanda, Tanzania, Uganda, Zambia, Cameroon, Burundi, Democratic Republic of Congo and Kenya.

Answer: product_or_material_produced