Analyze the relationship between 'Bharat Petroleum' and 'Petroleum' within the context of the input sentence.
Options: developer, position held, product/material produced, legal form

The Hindustan Petroleum Corp (HPCL) scrip fell 7.56%, while Bharat Petroleum Corp (BPCL) and the country’s biggest state-run refiner, Indian Oil Corp (IOC), declined 6-78% each.
product/material produced