Question: Elizabeth Christ Trump founded a real estate company with her son, who operated primarily in what city?

full_context: Document 1: Donald Trump Jr.: Donald John Trump Jr. (born December 31, 1977) is an American businessman and former reality TV personality. He is the oldest child of the 45th President of the United States, Donald Trump, and his first wife, Ivana.
Document 2: Marjorie Merriweather Post: Marjorie Merriweather Post (March 15, 1887 – September 12, 1973) was a leading American socialite and the owner of General Foods, Inc. She used much of her fortune to collect art, particularly pre-revolutionary Russian art, much of which is now on display at Hillwood, the museum that was her estate. She is also known for building Mar-a-Lago, an estate now owned by Donald Trump.
Document 3: Trump University: Trump University (also known as the Trump Wealth Institute and Trump Entrepreneur Initiative LLC) was an American for-profit education company that ran a real estate training program from 2005 until 2010. It was owned and operated by The Trump Organization. (A separate organization, Trump Institute, was licensed by Trump University but not owned by the Trump Organization.) After multiple lawsuits, it is now defunct. It was founded by Donald Trump and his associates, Michael Sexton and Jonathan Spitalny, in 2004. The company offered courses in real estate, asset management, entrepreneurship, and wealth creation.
Document 4: Elizabeth Christ Trump: Elizabeth Christ Trump (born Elisabeth Christ; October 10, 1880 – June 6, 1966) was a German-born American businesswoman and is considered the matriarch of the Trump family. She married Frederick Trump in 1902. While raising their three children, the early death of her husband in 1918 required her to manage his properties in order to support her family. She founded the real estate development company Elizabeth Trump & Son with her son Fred. The company, now known as The Trump Organization, is currently owned by her grandson, Donald Trump, who is the 45th President of the United States. Her great-grandsons, Donald Trump Jr. and Eric Trump are running the family business as trustees during their father's presidency.
Document 5: Donald Trump: Donald John Trump (born June 14, 1946) is the 45th and current President of the United States, in office since January 20, 2017. Before entering politics, he was a businessman and television personality.
Document 6: Fred Trump: Frederick Christ Trump Sr. (October 11, 1905 – June 25, 1999) was an American real estate developer and philanthropist, primarily in New York City, and father of Donald Trump, the 45th President of the United States, and Maryanne Trump Barry, a United States Court of Appeals judge.
Document 7: Donald Trump pseudonyms: American businessman, politician, and 45th President of the United States, Donald Trump, has used several pseudonyms, including "John Barron" (or "John Baron") and "John Miller". His habit of sometimes speaking to the media under the guise of a spokesperson has been described as "an open secret" at the Trump Organization and in New York media circles. Some New York editors recalled that "calls from Barron were at points so common that they became a recurring joke on the city desk." A writer for "Fortune" reported that Trump's father Fred Trump had used a pseudonym ("Mr. Green") in business dealings.
Document 8: Ivana Trump: Ivana Marie Trump (née Zelníčková , ] ; February 20, 1949) is a Czech-American businesswoman and former fashion model. She was the first wife of Donald Trump from 1977 until 1992.
Document 9: Ivanka Trump: Ivanka Trump ( born Ivana Marie Trump; October 30, 1981) is an American television personality, fashion designer, author and businesswoman who is an advisor to the President of the United States, Donald Trump. She is the daughter of the president and his first wife, former model Ivana Trump.
Document 10: Elisabeth Gürtler: Elisabeth Gürtler-Mauthner (born May 7, 1950) is an Austrian businesswoman. She is managing director of the Hotel Sacher, Vienna's most famous hotel.
Document 11: Frederick Trump: Frederick Trump (born Friedrich Trump; March 14, 1869 – May 30, 1918) was a German-American businessman. Born in Kallstadt, in the Kingdom of Bavaria (now in Rhineland-Palatinate, Germany), he emigrated to the United States at the age of 16 and started working as a barber. Several years later in 1891, he moved to the Northwest. He made his fortune operating boom-town restaurants and boarding houses in Seattle and a mining town to the north, and in the Klondike Gold Rush. He later returned to Germany and married. When authorities found that he had emigrated when young to avoid fulfilling his military service, he lost his Bavarian citizenship; he and his family returned to the United States.
Document 12: Charles Kushner: Charles Kushner (born May 16, 1954) is an American real estate developer. He founded Kushner Companies in 1985. In 2005, he was convicted of illegal campaign contributions, tax evasion, and witness tampering, and served time in federal prison. After his release, he resumed his career in real estate. His son is Jared Kushner, who is the husband of Ivanka Trump and son-in-law and senior advisor to President of the United States Donald Trump.
Document 13: Eric Trump: Eric Frederick Trump (born January 6, 1984) is an American businessman, philanthropist, and former reality TV personality. He is the third child and second son of the President of the United States, Donald Trump, and Ivana Trump. Alongside his older brother Donald Trump Jr., he serves as a trustee of The Trump Organization.
Document 14: Business career of Donald Trump: Donald Trump is an American businessman, former television personality, and the 45th President of the United States. He began his real estate career at his father's company, Elizabeth Trump and Son, which he later renamed to The Trump Organization. He rose to public prominence after a number of successful real estate deals in Manhattan and New York City, and his company now owns and develops lodging and golf courses around the world. Trump partly or completely owned several beauty pageants between 1996 and 2015. He has marketed his name to many building projects and commercial products. Trump's unsuccessful business ventures have included several casino and hotel bankruptcies, the folding of his New Jersey Generals football team, and the now-defunct Trump University.
Document 15: Joseph Kushner: Joseph Kushner (October 10, 1922 – October 5, 1985) was an American real estate magnate, and the father of Murray Kushner and Charles Kushner, and grandfather of Jared Kushner, Joshua Kushner, and Marc Kushner. He came to the US as a Holocaust survivor from Belarus in 1949. At the end of his career, he handed out to his successor control of 4,000+ apartments, houses, and properties.
ground_truth: New York City