Question: Speedway LLC is a wholly owned subsidiary of what corporation that was named best employer of the United States by Forbes in 2016?
Context: Speedway LLC is the operator of a combination gas station/convenience stores that is based in Enon, Ohio, United States with locations operating under its namesake brand along the Midwestern and East Coast of the United States.  Speedway LLC is a wholly owned subsidiary of the Marathon Petroleum Corporation and is the largest chain in central Ohio. Fuqi International (formerly traded as NASDAQ: FUQI ) is a designer of precious metal (gold and platinum) jewelry for the luxury goods market in China.  It also manufactures jewelry items that contain diamonds and other precious stones on a custom-order basis.  Fuqi is a Delaware corporation with its principal executive office located in Shenzen, China.  Fuqi operates through its wholly owned subsidiary, Fuqi International Holdings Co., Ltd., a British Virgin Islands corporation and its wholly owned subsidiary, Shenzhen Fuqi Jewelry Co., Ltd., a company established under the laws of China. ICE Clear Credit LLC ICE Clear Credit, a Delaware limited liability company, is a Derivatives Clearing Organisation (DCO) previously known as ICE Trust US LLC.  ICE Trust US LLC was launched in March 2009.  In 2009 ICE Trust became a New York chartered bank for purposes of Federal Reserve Act and was therefore eligible for membership in the Federal Reserve System.  ICE Clear Credit LLC operates as a central counterparty (CCP) and clearinghouse for credit default swap (CDS) transactions conducted by its participants.  ICE Clear Credit LLC is a subsidiary of IntercontinentalExchange (ICE).  ICE Clear Credit LLC is a wholly owned subsidiary of ICE US Holding Company LP (ICE LP) which is "organized under the law of the Cayman Islands but has consented to the jurisdiction of United States courts and government agencies with respect to matters arising out of federal banking laws (Federal Reserve System 2009)." Sun Hung Kai Financial Limited (SHKFL), is a 70%-owned subsidiary of Everbright Securities Company Limited (SSE: 601788, HKEX: 6178, “Everbright Securities”).  With its foundation dating back to 1969 when Fung King Hey, Kwok Tak Seng and Lee Shau Kee teamed up to start the Sun Hung Kai partnership, SHKFL was a wholly owned subsidiary of Sun Hung Kai & Co. Limited (SEHK: 86,　“SHKCO”).  SHKCO is chaired by Lee Seng Huang and controlled by the Lee & Lee Trust following the acquisition of the Fung family’s equity interest in the company by Allied Properties (H.K.) Limited via its wholly owned subsidiary in 1996.  In June 2015, Everbright Securities acquired 70% of SHKFL from SHKCO, making SHKFL a subsidiary of Everbright Securities since then.  SHKCO remains a 30% shareholder of SHKFL. Copperweld Corp. v. Independence Tube Corp., 467 U.S. 752 (1984) , is a major US antitrust law case decided by the Supreme Court concerning the Pittsburgh firm Copperweld Corporation and the Chicago firm Independence Tube.  It that held that a parent company is incapable of conspiring with its wholly owned subsidiary for purposes of Section 1 of the Sherman Act because they cannot be considered separate economic entities.  Section 1 of the Sherman Act states that "Every contract, combination in the form of trust or otherwise, or conspiracy, in restraint of trade or commerce among the several States, or with foreign nations, is declared to be illegal."  However, for a condition of conspiracy to exist, there must be at least two parties involved.  "Copperweld" held that separate incorporation was not enough to render a parent and its subsidiary capable of conspiring, since forcibly the economic interests of a wholly owned subsidiary must be those of its parent.  It does not apply to partially owned subsidiaries. DotCooperation LLC (dotCoop) is a wholly owned subsidiary of the U.S. based National Cooperative Business Association (NCBA) created in 2001 to manage the . coop top-level domain.  Midcounties Co-operative, through its subsidiary Midcounties Co-operative Domains, manages the technical operations of the . coop registry under a contract with dotCoop.  In 2012, Midcounties Co-operative Domains changed hands, to become simply Domains.coop, a wholly owned subsidiary of the International Co-operative Alliance (ICA). The Johnsonburg, Kane, Warren and Irvine Railroad (reporting mark JKWI) was a railroad company in Pennsylvania, United States, formed on May 24, 1982, by Sloan Cornell who also owned the Knox and Kane Railroad.  The JKWI was the designated operator of the Irvine, Warren, Kane & Johnsonburg Railroad, that was a partnership of Brock Railroad (a wholly owned subsidiary of Warren Car Company), Irvine Railroad (a wholly owned subsidiary of National Forge Company) and Struthers Wells Inter-American Corporation (a subsidiary of Struthers Wells), all three being Pennsylvania corporations, and had acquired from Conrail the following railroad line segments: MP 58.52 to MP 66.7 (Irvine to Warren) and MP 92.5 to MP 111.0 (Kane to Johnsonburg). John Hancock Financial is an informal term for a United States insurance company which existed, in various forms, from its founding on April 21, 1862, until its acquisition in 2004 by the Canadian insurance company Manulife Financial.  It was named in honor of John Hancock, a prominent Patriot.  The company continues to operate as a wholly owned subsidiary of Manulife and its headquarters remains in Boston, Massachusetts.  John Hancock Financial Network (JHFN) is the retail distribution company of John Hancock Life Insurance Company, U.S.A., which is a wholly owned subsidiary of Manulife Financial Corporation. The Murrin Murrin Joint Venture is a major nickel-cobalt mining operation being conducted in the North Eastern Goldfields, approximately 45 km east of Leonora, Western Australia.  The Project was a joint venture between Murrin Murrin Holdings Pty Ltd, a wholly owned subsidiary of Minara Resources Ltd (whose share is 60%) and Glenmurrin Pty Ltd, a wholly owned subsidiary of Glencore International AG, which had a 40% share but also owned 70% of Minara.  As of November 2011, Minara Resources was fully acquired and is now wholly owned by Glencore International.  The mine opened in 1999. Marathon Petroleum Corporation is an American petroleum refining, marketing, and transportation company headquartered in Findlay, Ohio.  It was elected the best employer of United States in 2016 by Forbes.  The company was a wholly owned subsidiary of Marathon Oil until a corporate spin-off in 2011.
Answer: Marathon Petroleum Corporation