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?
Analyze the relationship between 'Tullow Oil' and 'Petroleum' within the context of the input sentence.
Options: creator, member of, product/material produced, owner of