Wed, Jul 15, 2015, 11:40 BST - UK Markets close in 4 hrs 50 mins When Will It Be Time To Buy Explorers Gulf Keystone Petroleum Limited, Enquest Plc And Tullow Oil plc?
In the context of the input sentence, determine the relationship between 'Tullow Oil' and 'Petroleum'.
Options: creator, member of, owner of, product/material produced