Question: Pieter 'Piet' Klijnveld, was a Dutch accountant who started a practice that after several mergers would grow into which professional service company and one of the Big Four auditors, along with Deloitte, Ernst & Young (EY), and PricewaterhouseCoopers (PwC)?

full_context: Document 1: James Marwick: James Marwick (b. 1862 in Edinburgh, Scotland) was an original founder of an accounting office that became one of the Big Four auditors, KPMG.
Document 2: Klynveld Kraayenhof &amp; Co.: Klynveld Kraayenhof & Co. (KKC) was a Dutch accountancy firm founded in 1917 by Piet Klijnveld and Jaap Kraayenhof, who was one of Klynveld's former employees at another firm. The firm specialized in banking and exporting and kept its independence by serving Dutch clients who were expanding throughout Europe and South America. In 1979, KKC merged with Deutsche Treuhand-Gesellschaft (DTG) and McLintock Main Lafrentz to form Klynveld Main Goerdeler (KMG). In 1987 KMG joined forces with Peat Marwick International (PMI) in the first mega-merger of large accounting firms and formed what is now known today as KPMG LLP.
Document 3: WTP Advisors: WTP Advisors is an international-tax advisory and consultancy firm. Inc. Magazine ranked the company as one of the fastest growing businesses in the United States in 2011, 2012, 2013. The 2012 Inc. 500 and 5000 survey ranked WTP Advisors at 1,184; within the business products and services category, the company ranked 75th. The company was founded in 2005 by Ian Boccaccio, Michael Minihan, David Wain and James Fyhrie all former employees of PricewaterhouseCoopers. The partners saw an opportunity to provide international tax consulting for small and medium businesses and be competitive with the “Big Four” accounting firms: PricewaterhouseCoopers, Ernst & Young, Deloitte Touche Tohmatsu and KPMG.
Document 4: Ernst &amp; Young: EY (formerly Ernst & Young) is a multinational professional services firm headquartered in London, England. EY is one of the largest professional services firms in the world and is one of the "Big Four" accounting firms.
Document 5: Jon C. Madonna: Jon C. Madonna, retired, was most recently chairman and chief executive officer of KPMG (a professional services firm), in New York City. He was with KPMG for 28 years, where he held numerous senior leadership positions throughout his career, including chairman from 1990 to 1996. Subsequent to his retirement from KPMG in 1996, Madonna served as vice chairman of Travelers Group, Inc. from 1997 to 1998, and president and chief executive officer of Carlson Wagonlit Corporate Travel, Inc. from 1999 to 2000. He was chief executive officer of DigitalThink, Inc. from 2001 to 2002 and chairman of DigitalThink, Inc. from April 2002 to May 2004. Madonna is a director of AT&T Inc., Phelps Dodge Corporation, Tidewater Inc. and Visa U.S.A. Inc.
Document 6: Sven Erik Holmes: Sven Erik Holmes (born 1951) is a former United States District Judge of the United States District Court for the Northern District of Oklahoma and currently the Vice Chairman, Legal, Risk and Regulatory, and Chief Legal Officer for KPMG LLP, a global accounting firm. He directs the office of general counsel, risk management, government affairs, security, and ethics and compliance programs. He is also counsel to the board of directors and a member of the management committee. He is currently chairman of the board for the Council for Court Excellence. In 2009, "Ethicsphere" named him one of America's 100 most influential people in business ethics. In 2007, "Accounting Today" named him one of the "Top 100 Most Influential People in Accounting." In 2014, National Law Journal named him "America's 50 Outstanding General Counsel."
Document 7: Eugene O'Kelly: Eugene O'Kelly was a former Chairman and CEO of KPMG, one of the largest U. S. accounting firms and one of the Big Four auditors.
Document 8: Diamond Management &amp; Technology Consultants: Diamond Management & Technology Consultants (casually referred to as Diamond) was an independent management consulting firm founded in 1994, headquartered in Chicago, IL with satellite offices in Hartford, CT, New York City, Washington DC, London, and Mumbai. It was acquired by the British firm, PwC in 2010. Diamond was a smaller player among companies such as Mercer Management Consulting, Deloitte Consulting, and Accenture. The industry segments under which Diamond operated include consumer packaged goods, financial services, and health-care, among numerous others.
Document 9: PricewaterhouseCoopers: PricewaterhouseCoopers (doing business as PwC) is a multinational professional services network headquartered in London, United Kingdom. It is the second largest professional services firm in the world, and is one of the Big Four auditors, along with Deloitte, EY and KPMG. Vault Accounting 50 has ranked PwC as the most prestigious accounting firm in the world for seven consecutive years, as well as the top firm to work for in North America for three consecutive years.
Document 10: Arthur Andersen: Arthur Andersen LLP, based in Chicago, is an American holding company and formerly one of the "Big Five" accounting firms among PricewaterhouseCoopers, Deloitte Touche Tohmatsu, Ernst & Young and KPMG, providing auditing, tax, and consulting services to large corporations. In 2002, the firm voluntarily surrendered its licenses to practice as Certified Public Accountants in the United States after being found guilty of criminal charges relating to the firm's handling of the auditing of Enron, an energy corporation based in Texas, which had filed for bankruptcy in 2001.
Document 11: Accounting: Accounting or accountancy is the measurement, processing, and communication of financial information about economic entities such as businesses and corporations. The modern field was established by the Italian mathematician Luca Pacioli in 1494. Accounting, which has been called the "language of business", measures the results of an organization's economic activities and conveys this information to a variety of users, including investors, creditors, management, and regulators. Practitioners of accounting are known as accountants. The terms "accounting" and "financial reporting" are often used as synonyms.
Document 12: KPMG: KPMG is a professional service company and one of the Big Four auditors, along with Deloitte, Ernst & Young (EY), and PricewaterhouseCoopers (PwC).
Document 13: Big Four accounting firms: The Big Four are the four largest professional services networks in the world, offering audit, assurance services, taxation, management consulting, advisory, actuarial, corporate finance and legal services. They handle the vast majority of audits for public companies as well as many private companies. It is reported that the Big Four audit 99% of the companies in the FTSE 100, and 96% of the companies in the FTSE 250 Index, an index of the leading mid-cap listing companies.
Document 14: Piet Klijnveld: Pieter 'Piet' Klijnveld (16 August 1874 – 9 February 1945) was a Dutch accountant who started a practice that after several mergers would grow into the international accounting firm KPMG.
Document 15: Expert Global Solutions: Founded in 2012, Expert Global Solutions, Inc., ("EGS", formerly NCO Group), based in Plano, Texas, is the world's largest privately owned Business Process Outsourcing company with more than 100 locations globally and more than 40,000 associates. It is a holding company for NCO and APAC Customer Services, Inc. (APAC), providers of global business process outsourcing services. NCO provides accounts receivable management (ARM) services, and APAC provides customer relationship management (CRM) services. EGS has over 100 locations, with more than 42,000 employees. EGS is owned by One Equity Partners (OEP), the private investment arm of JP Morgan Chase & Co.
ground_truth: KPMG