Question: Which University is ranked 20th in the world in 2017 by the Academic Ranking of World Universities, California Institute of Technology or Washington University in St. Louis?

Context paragraphs:
Washington University in St. Louis: Washington University in St. Louis (also referred to as WashU, or WUSTL) is a private research university located in the St. Louis metropolitan area and in Missouri, United States.  Founded in 1853, and named after George Washington, the university has students and faculty from all 50 U.S. states and more than 120 countries.  Twenty-five Nobel laureates have been affiliated with Washington University, nine having done the major part of their pioneering research at the university.  Washington University's undergraduate program is ranked 18th by "U.S. News & World Report" in 2018 and 11th by the Wall Street Journal in their 2018 rankings.  The university is ranked 20th in the world in 2017 by the Academic Ranking of World Universities.

QS World University Rankings: QS World University Rankings is an annual publication of university rankings by Quacquarelli Symonds (QS).  Previously known as "Times Higher Education–QS World University Rankings", the publisher had collaborated with "Times Higher Education magazine" ("THE") to publish its international league tables from 2004 to 2009 before both started to announce their own versions.  QS then chose to still use the pre-existing methodology while "Times Higher Education" adopted a new methodology.  The QS system now comprises the global overall and subject rankings (which name the world's top universities for the study of 46 different subjects and five composite faculty areas), alongside five independent regional tables (Asia, Latin America, Emerging Europe and Central Asia, the Arab Region, and BRICS).  It is the only international ranking to have received International Ranking Expert Group (IREG) approval, and is viewed as one of the most widely read of its kind, along with "Academic Ranking of World Universities" and "Times Higher Education World University Rankings".  However, allocating undue weight to subjective indicators and having highly fluctuating results are its major criticisms.

University of Oslo: The University of Oslo (Norwegian: "Universitetet i Oslo" ), until 1939 named the Royal Frederick University (Norwegian: "Det Kongelige Frederiks Universitet" ), is the oldest university in Norway, located in the Norwegian capital of Oslo.  Until 1 January 2016 it was the largest Norwegian institution of higher education in terms of size, now surpassed only by the Norwegian University of Science and Technology.  The Academic Ranking of World Universities has ranked it the 58th best university in the world and the third best in the Nordic countries.  In 2015, the Times Higher Education World University Rankings ranked it the 135th best university in the world and the seventh best in the Nordics.  While in its 2016, Top 200 Rankings of European universities, the Times Higher Education listed the University of Oslo at 63rd, making it the highest ranked Norwegian university.

Autonomous University of Madrid: The Autonomous University of Madrid (Spanish: "Universidad Autónoma de Madrid" ; informally "La Autónoma"), commonly known by the Spanish acronym UAM, is a Spanish public university established in 1968.  It is located in northern Madrid; its main campus, Cantoblanco, is located near the cities of Alcobendas, San Sebastián de los Reyes and Tres Cantos.  Throughout its history, UAM has been one of Spain's most prominent higher education institutions, being ranked first amongst Spanish universities by the El Mundo University Supplement (known as "Las 50 Carreras"), by The Times Higher Education Supplement, and by the Academic Ranking of World Universities yearly published by Shanghai Jiao Tong University.  For the subject "Mathematics" the university was ranked within top 51-75 universities in the world (within top 12 in Europe).  In the "Times Higher Education 100 Under 50 University Rankings", the University achieved 49th position globally in 2012.  In another similar ranking "QS Top 50 Under 50" by Quacquarelli Symonds (QS), the Autonomous University of Madrid recently achieved 9th place in international comparison.  Its Faculty of Law is the most prestigious one in Spain.  It is the Spanish university with the most researchers among the most cited according to the Thomson Reuters ranking citation in 2011.

Academic Ranking of World Universities: Academic Ranking of World Universities (ARWU), also known as Shanghai Ranking, is an annual publication of university rankings by Shanghai Ranking Consultancy.  The league table was originally compiled and issued by Shanghai Jiao Tong University in 2003, the first global ranking with multifarious indicators, after which a board of international advisories was established to provide suggestions.  The publication currently includes global league tables for institutions and a whole and for a selection of individual subjects, alongside independent regional "Greater China Ranking" and "Macedonian HEIs Ranking".  ARWU is regarded as one of the three most influential and widely observed university measures, alongside "QS World University Rankings" and "Times Higher Education World University Rankings".  It is praised for its objective methodology but draws some condemnation for narrowly focusing on raw research power, undermining humanities and quality of instruction.

California Institute of Technology: The California Institute of Technology (abbreviated Caltech) is a private doctorate-granting university located in Pasadena, California, United States.

Tufts University School of Medicine: The Tufts University School of Medicine is one of the eight schools that constitute Tufts University.  The "Times Higher Education (THE)" and the "Academic Ranking of World Universities (ARWU)" consistently rank Tufts among the world's best medical research institutions for clinical medicine.  Located on the university's health sciences campus in downtown Boston, Massachusetts, the medical school has clinical affiliations with thousands of doctors and researchers in the United States and around the world, as well as at its affiliated hospitals in both Massachusetts (including Tufts Medical Center, St. Elizabeth's Medical Center, Lahey Hospital and Medical Center and Baystate Medical Center), and Maine (Maine Medical Center).  According to Thomson Reuters' "Science Watch", Tufts University School of Medicine's research impact rates sixth among U.S medical schools for its overall medical research and within the top 5 for specialized research areas such as chronic obstructive pulmonary disorder, urology, cholera, public health & health care science, and pediatrics.  In addition, Tufts University School of Medicine is ranked 44th in research and 38th in primary care according to "U.S. News & World Report".

South China University of Technology: South China University of Technology (SCUT; , orally known as Huágōng 华工) is a major public university in China.  It is located in the Tianhe District and Panyu District of Guangzhou, capital of Guangdong Province, China.  It is a multidisciplinary university focusing on engineering, combined with science, also promoting well coordinated development of management, economics, humanities and law.  Its engineering ranks top 50 among world universities according to Academic Ranking of World Universities (ARWU).

University of Szeged: The University of Szeged (Hungarian: Szegedi Tudományegyetem ,    ) is a large research university in Hungary.  It is located in Hungary's third-largest city, Szeged, in Csongrád County in the Southern Great Plain.  The University is one of Hungary's most important universities and is among the most prominent higher education institutions in Central Europe.  According to the "Academic Ranking of World Universities" by Shanghai Jiao Tong University (2003, 2004, 2005), it was ranked 203rd–300th in the complete list (in a tie), 80th–123rd in the scientific ranking of European universities, and first in the Hungarian national ranking.  In 2013 it was ranked 401-500 in the world, 124th–168th in the scientific ranking of European universities, and second in the national ranking.  In 2014, the QS World University Rankings put the University of Szeged as 501-550 among universities globally.  Its highest ranked subject area was Modern Languages with 101-150 globally.  The University's operating budget for 2014 was US$220 million.

National and Kapodistrian University of Athens: The National and Kapodistrian University of Athens (NKUA; Greek: Εθνικόν και Καποδιστριακόν Πανεπιστήμιον Αθηνών, "Ethnikón kai Kapodistriakón Panepistímion Athinón" ), usually referred to simply as the University of Athens (UoA), is a public university in Zografou, a suburb of Athens, Greece.  It has been in continuous operation since its establishment in 1837 and is the oldest higher education institution of the modern Greek state and the first contemporary university in the Eastern Mediterranean.  Today it is one of the largest universities by enrollment in Europe, with 104,000 (2014) registered students.  In 2012 it was ranked in the positions 501–550 among the best universities in the world, according to the index of QS World University Rankings, as well as according to the evaluation of Academic Ranking of World Universities (ARWU).

Supporting paragraphs: California Institute of Technology Washington University in St. Louis
Answer: Washington University in St. Louis