What is the relationship between Marathon Oil and Petroleum 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.

Both Marathon Petroleum and Phillips 66 were the downstream arms spun off from their parents in 2011 — Houston-based Marathon Oil Corp. (NYSE: MRO) and Houston-based ConocoPhillips (NYSE: COP).
product_or_material_produced