Question: Louis Barnett became the youngest supplier of an employee-owned retailer under which partnership?

Context paragraphs:
Samuel Moody Grubbs House: The Samuel Moody Grubbs House is a historic house located at 805 E. Union Ave. in Litchfield, Illinois.  The house was built in 1873-74 for Samuel Moody Grubbs, a banker who later became Litchfield's mayor.  George Ingham Barnett, a prominent St. Louis architect, designed the Second Empire house; it is the only standing Barnett design in Illinois.  The design is typical of the second half of Barnett's career, when he shifted from Italianate to Second Empire designs, and represents a popular style in postbellum America.  A mansard roof with slate tiles tops the house; a cornice running along the roofline features paired brackets.  The front of the house features a wraparound porch supported by columns.  The house's corners have bold quoins.  In a deviation from the typical rectangular plans of Second Empire houses, Barnett gave the house a cross axis plan with projecting wings.

Thomas P. Barnett: Thomas P. Barnett (February 11, 1870 – September 23, 1929), also known professionally as Tom Barnett and Tom P. Barnett, was an American architect and painter from St. Louis, Missouri.  Barnett was nationally recognized for both his work in architecture and in painting.

Saint Clement Catholic Church, Chicago: St. Clement Catholic Church was built in 1917-1918 in Lincoln Park in Chicago.  The architect was Thomas P. Barnett of the St. Louis firm of Barnett, Haynes & Barnett.

Electricity billing in the UK: In the UK, an electricity supplier is a retailer of electricity.  For each supply point the supplier has to pay the various costs of transmission, distribution, meter operation, data collection, tax etc.  The supplier then adds in energy costs and the supplier's own charge.

Pay 'n Save: Pay 'n Save was a retail company founded by Monte Lafayette Bean in Seattle, Washington; 1940.  Over the years, Pay 'n Save was the leading drugstore chain in Washington and was the owner of several Washington-based retailers including Lamonts and Ernst.  A 1984 sale of the company to The Trump Group and a 1986 attempt to transform the retailer into a bargain-basement merchandiser resulted in a loss of nearly $50 million.  By 1988, Pay 'n Save was sold to Thrifty Corporation who later sold the stores to PayLess Drug who retired the Pay 'n Save name.  As a result, most of the retailer's divisions were spun off as separate companies or shuttered.  As of 2011, Pay 'n Save's membership discount chain, Bi-Mart, is the lone surviving division of the company (as of 2017, Bi-Mart is an employee-owned company).

Henry Walter Barnett: Henry Walter Barnett (25 January 1862 – 16 January 1934), usually known as H. Walter Barnett, was an Australian photographer and filmmaker.  Barnett was a prominent portrait photographer of the late 19th and early 20th centuries, establishing the successful Falk studios in Sydney.  Later in his career he was based in London, England, with studios at Hyde Park Corner and Knightsbridge.  Barnett became involved in filmmaking after meeting cinematographer Marius Sestier in 1896, and with Sestier made some of the first films shot in Australia.

Louis Barnett (chocolatier): Louis Barnett (born 2 November 1991) from Kinver, Staffordshire is a licensed chocolatier who became the youngest supplier of both the Sainsbury's and Waitrose supermarket chains at the age of 14.  He left school at the age of 11 because of learning difficulties and was later diagnosed with dyslexia and developmental coordination disorder.  His parents continued his education through homeschooling.  He started making chocolates for friends and family and in 2005 he started his company Chokolit Ltd. to deal with the growing demand.  Winner of " Emerging Entrepreneur of the Year Award " 2011 .  He received the Lord Carter Award for excellence in the food industry, presented to him in The House Of Lords 2009, was nominated for a Young Entrepreneur of the Year Award in 2007.  He was also a finalist in the teen category of the 2007 Enterprising Young Brits Awards.

Louis Barnett Abrahams: Louis Barnett Abrahams (3 October 1839–3 June 1918) was a Welsh-born, English Jewish educator, the headmaster of the Jews' Free School in London.

Jackson Barnett: Jackson Barnett (1 January 1856 – 29 May 1934) was an Oklahoma landowner of the Muscogee or Creek people, who became known as "the world's richest Indian" when oil wells on his land produced as much as $24 million worth of oil starting in 1912.  Barnett's 12.5% royalty share was worth between $3 million and $4 million, but due to Barnett's illiteracy and a court finding that Barnett was legally incompetent from a head injury, his money was administered by the Creek County courts and the U.S. Department of the Interior until 1920.

Waitrose: Waitrose is a chain of British supermarkets, which forms the food retail division of Britain's largest employee-owned retailer, the John Lewis Partnership.  Its head office is located in Bracknell, Berkshire, England.  As of February 2015, Waitrose has 350 branches across the United Kingdom, including 30 "little Waitrose" convenience stores, and a 5.1% share of the market, making it the sixth-largest grocery retailer in the UK.

Supporting paragraphs: Louis Barnett (chocolatier) Waitrose
Answer: John Lewis Partnership