Question: Which business that includes Dursun Aydın Özbek is located in Istanbul?
Context: Istanbul Sapphire, or Sapphire, is a skyscraper, and as of 2016, the tallest building in Istanbul and Turkey, located in the central business district of Levent.  Istanbul Sapphire was the 4th tallest building in Europe when its construction was completed in 2010.  It is the country's first ecological skyscraper.  Sapphire rises 54 floors above ground level, and boasts an above-ground roof height of 238 meters: the building has an overall structural height of 261 meters including its spire, which is part of the design and not a radio antenna.  Designed by Tabanlıoğlu Architects, it is a shopping and luxury residence mixed-use development managed by Kiler GYO. Dursun Aydın Özbek (born 25 March 1949) is a Turkish businessman.  He is the chairman of Galatasaray S.K.. Levent is a neighbourhood and one of the main business districts of Istanbul, Turkey, located on the European side of the city.  It is a part of the municipality of Beşiktaş which is situated to the north of the Golden Horn, at the western shore of the Bosphorus strait. This is a list of busiest airports in Asia, ranked by total passengers per year, which includes arrival, departure and transit passengers.  Beijing Capital International Airport has been the busiest airport in Asia since 2009.  The tables also shows the percentage change in total passenger traffic over last year.  Asian airports are those that are located in the 48 countries and 6 dependent states as defined by UN and fall within the Asian region.  Airports in Moscow and Istanbul airport are located in the European part of their respective countries and so are not included in this list.  While Turkey is a member state of The Council of Europe which includes Turkish airspace within Europe and hence traffic of Turkish airports, even those falling in the Asian region, are included in the busiest airport in Europe list. John Cook School of Business is the business school of Saint Louis University, a Jesuit, Catholic university located in St. Louis, Missouri.  The business school was founded in 1910 and is the oldest business school west of the Mississippi River and 15th oldest in the United States.  The John Cook School of Business undergraduate and graduate programs are accredited by AACSB International—the Association to Advance Collegiate Schools of Business, the premier accrediting agency for degree programs in business—in which it earned accreditation in 1948.  Less than 5% of business schools worldwide have earned accreditation.  The student body includes more than 1,700 undergraduates and graduates.  It is named after John M. Cook, Chairman and C.E.O. of PRG-Schultz International, Inc. Kanyon (meaning Canyon in Turkish) is a multi-purpose complex located on the Büyükdere Avenue in the Levent business district of Istanbul, Turkey.  Opened on 6 June 2006, it unites a 160-store shopping mall (covering an area of 37,500 m), a 30-floor office tower (26 floors of which rise above street level) and a 22-floor residential block with 179 residential apartments into a complex undulating around a dramatic architectural “canyon”.  The total construction area of the project is 250,000 m, with 30,000 m of rentable office area, 37,500 m of rentable retail area, 180 residential flats, 160 stores, 9 theater halls with a capacity of 1,600 spectators, and a parking facility for 2,300 vehicles.  Each floor of the office tower has a total usable office space of 1,167 m.  The complex rises on an area of 29,427 m. Varyap Meridian Project is a mixed-use development located near Istanbul's new financial and business district.  Varyap Meridian Grand Tower is the tallest building in this project, at 244 m. Mecidiyeköy is a neighbourhood located in the Şişli district of Istanbul, Turkey.  It is also one of the prominent business quarters of Istanbul.  It is situated between Fulya, Kuştepe, Gültepe, Esentepe, and Gülbahar neighbourhoods.  According to the 2008 demographic data, the population of the neighbourhood is 20,331. Galatasaray Spor Kulübü (] , "Galatasaray Sports Club") is a Turkish sports club based on the European side of the city of Istanbul in Turkey, most notable for its association football department.  The club also consists of various other departments including basketball, wheelchair basketball, volleyball, water polo, handball, athletics, swimming, rowing, sailing, judo, bridge, motorsport, equestrian, and chess.  Galatasaray S.K. is among the key members of the Galatasaray Community Cooperation Committee together with Galatasaray University and the prestigious Lycée de Galatasaray. Volkswagen Arena Istanbul is a multi-purpose indoor arena that is located in Istanbul, Turkey.  The arena can be used to host live events, such as concerts, fashion shows, award ceremonies, dance and theater shows, basketball games, and other sporting events.  The capacity of the arena ranges from 4,500 to 5,800, depending on different configurations for different events, and a combination of seating, standing, and VIP box configurations.  The arena's capacity for basketball games is 5,240, which includes 5,000 regular seats for fans (88 of which are VIP seats), and 240 available seats in the arena's 24 private lounge suites.
Answer: Galatasaray S.K.