What is the relationship between 'Repsol' and 'Petroleum' in the context of the input sentence.
Options: chief executive officer, brand, creator, product/material produced

BP, Statoil (Xetra: 675213 - news ) , Anadarko Petroleum Corp. , Repsol and Total (Swiss: FP.SW - news ) are the main foreign energy firms in Algeria.
product/material produced