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).
Refer to the input text as context and select the correct relationship between 'ConocoPhillips' and 'Petroleum' from the available options.
Options: product/material produced, founded by, creator, manufacturer