Question: Simon Roberts is the former managing director of which pharmacy chain?
Context: Simon John Roberts (born 26 January 1971) is a British businessman and former managing director of Boots UK. Apotek 1 Gruppen AS is a Norwegian pharmacy wholesaler ("Apokjeden Distribusjon AS") and retailer (Apotek 1) owned by German Phoenix Pharmahandel.  It owns the largest pharmacy chain in Norway, Apotek 1.  The company started a cooperation with a number of pharmacists who wanted a wholesaler independent of the state owned Norsk Medisinaldepot in 1995, when most pharmacies in the country joined the company.  1997 saw the first attempts to brand the pharmacies, as Plussapotek.  The first branded pharmacy as Apotek 1 was launched in 1999 in Manglerud Senter.  In 2001, the pharmacy market was deregulated, and Tamro was at first chosen as a wholesaler, before eventually buying the entire company in 2004. Uniprix is a Quebec pharmacy chain founded in 1977 and based in Saint-Leonard, Montreal.  It operates under four brands: Uniprix, Unipharm, Clinique Santé and Uniclinique (inside clinics).  Combining its four brands, Uniprix is the second-largest pharmacy chain in Quebec (after Jean Coutu) and is mutually exclusive with the Pharmasave chain in English Canada. Thrifty White Pharmacy (also known as White Drug and Thrifty Drug) is an American pharmacy chain with operations in six states, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, and Iowa headquartered in Plymouth, MN.  It specializes in filling prescriptions, long term care consulting, community outreach, and specialty services.  As of September 2016, Thrifty White received full URAC accreditation for its specialty pharmacy. Mangu Singh (born 15 December 1955) is managing director of Delhi Metro.  He took over as managing director after E. Sreedharan, the former managing director, retired from service on 31 December 2011.  He is an Indian Railways Service of Engineers (IRSE) officer of the 1981 batch. Hartig Drug Stores is a chain of pharmacy/retail stores based out of Dubuque, Iowa.  The company provides pharmacy services not only to the general public, but to area institutions as well.  Along with this pharmacy focus, Hartig Drug stores offer convenience retail items.  The company has operated for over 100 years; currently, it is the second-oldest family-run pharmacy chain in the United States. Benzer Pharmacy formerly known as Rx Care Pharmacy is an independent pharmacy chain in the United States with more than sixty-five stores.  Headquartered in Tampa, Florida, the retail pharmacy ranks position 1500 in the 2015 Inc. 5000 for the fastest growing private company in America and position 39 out of 100 in the 2015 Florida Fast 100 for the fastest-growing private companies in Florida. Boots UK (formerly Boots the Chemists Ltd.), trading as Boots, is a pharmacy chain in the United Kingdom, Ireland, Norway, Thailand and other territories.  The company's former parent, The Boots Company Plc, merged with Alliance UniChem in 2006 to form Alliance Boots.  In 2007, Alliance Boots was bought by Kohlberg Kravis Roberts and Stefano Pessina, taking the company private, and moving its headquarters to Switzerland, the first ever FTSE 100 company bought by a private equity firm.  In 2012, Walgreens bought a 45% stake in Alliance Boots, with the option to buy the rest within three years.  It exercised this option in 2014, and as a result Boots became a subsidiary of the new company, Walgreens Boots Alliance, on 31 December 2014. Well, formerly The Co-operative Pharmacy, is the largest independent pharmacy business and the third largest overall pharmacy chain after Boots the Chemists and Lloyds Pharmacy (except in Wales, where Well is the biggest chain overall) in the United Kingdom. Navarro Discount Pharmacies, Inc., frequently referred to as Navarro is a pharmacy chain, photo service, and pharmacy benefit manager in the United States.  The company was acquired by CVS Pharmacy in September, 2014 and is operated as a separate brand and business of CVS, headquartered in Miami, Florida.  The company mainly operates in Miami-Dade and Broward Counties and currently has 28 stores.  Navarro Discount Pharmacies has a 17% market share in South Florida, ahead of Walgreens and CVS/pharmacy.
Answer: Boots UK