Question: Which Wharton, University of Pennsylvania graduate served as chairman of the largest manufacturer of tractors in the world?

Context paragraphs:
Jon Spector: Jonathan Spector is president and chief executive officer of The Conference Board.  Spector, a graduate of Wesleyan University and Harvard Business School, joined The Conference Board after serving as vice dean of The Wharton School at the University of Pennsylvania.  During his tenure at Wharton School, Spector was responsible for the significant growth and strategic repositioning of the school’s executive education activities, and for strengthening Wharton’s involvement in book publishing, globalization and collaborations across the university.  Before joining The Wharton School he spent 20 years with McKinsey & Company, where he was a senior partner in the firm.  He serves on the board of directors of The Demand Institute, The Conference Board of Canada, and the March of Dimes Foundation.  He is the co-author of We Are Smarter Than Me (2007), which highlights the ways in which businesses can harness the power of collective intelligence.

John Fries Frazer: John Fries Frazer (8 July 1812 – 12 October 1872) was a University of Pennsylvania graduate and first assistant geologist to the Geological Survey of Pennsylvania.  He became a professor of Natural philosophy and Chemistry and in later years he became Vice Provost of the University of Pennsylvania.

Kumsong Tractor Factory: The Kŭmsŏng Tractor Factory, located in Kiyang-dong, Kangsŏ-guyŏk, Namp'o, is North Korea's largest manufacturer of tractors, bulldozers, and other agricultural equipment.  Employing around 10,000 workers, the factory has a floor area of 142,000 m2 on a total area of 400,000 m2 .  Although it has a production capacity of 10,000 tractors per year, at present the average annual output is around 200 tractors.  The factory's current products include the "Ch'ŏllima 28" 28 hp , "Ch'ŏllima 32" 32 hp , "Ch'ŏllima 40" 40 hp , "P'ungnyŏn 75" 75 hp , "Sonyŏn" 45 hp and "Ch'ŏllima 2000" tractors, and the "P'ungnyŏn" bulldozer.  This factory also produces TEL mobile missile platforms.

Peter Linneman: Dr. Peter Linneman (born March 24, 1951) is the principal of Linneman Associates, the CEO and founder of American Land Fund and of KL Realty.  He previously served as the Albert Sussman Professor of Real Estate, Finance, and Public Policy at the Wharton School of the University of Pennsylvania in Philadelphia, Pennsylvania, retiring in December 2010.  Linneman served as the founding chairman of Wharton's Real Estate Department, and was the Director of Wharton's Samuel Zell and Robert Lurie Real Estate Center for 13 years.  He is also the founding co-editor of the "Wharton Real Estate Review".  Linneman has also been named one of the 100 Most Powerful People in New York real estate according to "The New York Observer" and one of the 25 most influential people in commercial real estate by "Realtor Magazine".

Wharton School of the University of Pennsylvania: The Wharton School of the University of Pennsylvania ( ; also known as the Wharton School or simply Wharton) is the business school of the University of Pennsylvania, a private Ivy League university located in Philadelphia, Pennsylvania.  Wharton was established in 1881 through a donation from Joseph Wharton and is the world’s first collegiate school of business.

James A. McKernan: James McKernan (born November 7, 1945) is an American and Irish citizen and educational theorist.  He is Professor of Education at East Carolina University, a constituent campus of the University of North Carolina.  He has been the King Distinguished Professor and Chair of Education at East Carolina University; Dean and Chair of the Faculty of Education at the University of Limerick, Ireland; College Lecturer, Faculty of Arts, University College Dublin, Ireland and Fulbright Scholar at the Harvard Graduate School of Education and University of Pennsylvania Graduate School of Education and Research Fellow, Northern Ireland Council for Educational Research, Department of Psychology, Queen's University of Belfast. Professor McKernan has taught Palestinian university students when Israel closed schools and colleges there.

Mahindra &amp; Mahindra: Mahindra and Mahindra Limited (M&M) is an Indian multinational car manufacturing corporation headquartered in Mumbai, Maharashtra, India.  It is one of the largest vehicle manufacturers by production in India and the largest manufacturer of tractors in the world.  It is a part of Mahindra Group, an Indian conglomerate.

Mahindra Tractors: Mahindra Tractors is an international farm equipment manufacturer of Mahindra & Mahindra.  In 2010, Mahindra became the world's highest-selling tractor brand by volume.  Mahindra's largest consumer base is in India, China, North America, and a growing market in Australia.  The company is the largest manufacturer in India and has the capacity to build 150,000 tractors a year.

YTO Group: The YTO Group Corporation is a Chinese agriculture and construction machinery manufacturer that is part of Sinomach, a comprehensive machinery conglomerate.  Although composed of many subsidiaries and divisions that manufacture a range of products including agricultural tractors, engines, combine harvesters and trucks, the company is best known for farming equipment.  The company was founded in 1955 is the largest manufacturer of tractors in China.  A subsidiary of the company operates under the name China First Tractor.

Keshub Mahindra: Keshub Mahindra (9 October 1923) is an Indian businessman, and the chairman emeritus of the Mahindra Group.  He retired as chairman in August 2012 after heading the Group for nearly five decades, handing over the position to his nephew, Anand Mahindra.  Mahindra is known for his philanthropy.  He is a graduate from Wharton, University of Pennsylvania, US.  He joined Mahindra & Mahindra in 1947, and in 1963 took over as chairman.

Supporting paragraphs: Keshub Mahindra Mahindra &amp; Mahindra
Answer: Keshub Mahindra