In this task, you are given a context, a subject, a relation, and many options. Based on the context, from the options select the object entity that has the given relation with the subject. Answer with text (not indexes).

Context: The Minor Planet Center (MPC) is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids) and comets, calculating their orbits and publishing this information via the "Minor Planet Circulars". Under the auspices of the International Astronomical Union, it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory., La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several telescopes are located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO., Rozhen Observatory ("-" "NAO-Rozhen"), also known as the Bulgarian National Astronomical Observatory, is a astronomical observatory, located in the Smolyan Province, 90 kilometers south of the city of Plovdiv, Bulgaria. The nearest town, Chepelare, is 15 kilometers away. The observatory is owned and operated by the Institute of Astronomy of the Bulgarian Academy of Sciences (BAS). It was officially opened on 13 March 1981, almost 20 years after Bogomil Kovachev  a professor of astronomy at BAS, known as its founder  had started working towards that goal. The Observatory is the largest in Southeastern Europe and has an active team of about 50 astronomers. It is the principal center for astronomical research in Bulgaria. The minor planet 6267 Rozhen, was discovered at, and named after the observatory., The Royal Observatory of Belgium, is situated in Uccle (Ukkel in Dutch) since 1890. It was first established in Saint-Josse-ten-Noode in 1826 by William I under the impulse of Adolphe Quetelet. It was home to a 100 cm diameter aperture Zeiss reflector in the first half of the 20th century, one of the largest telescopes in the world at the time. It owns a variety of other astronomical instruments, such as astrographs, as well as a range of seismograph equipment (such as for detecting earthquakes)., The European Southern Observatory (ESO, formally: "European Organization for Astronomical Research in the Southern Hemisphere") is a 16-nation intergovernmental research organization for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs about 730 staff members and receives annual member state contributions of approximately €131 million. Its observatories are located in northern Chile., Eric Walter Elst (b.1936) is a Belgian astronomer at the Observatory at the Royal Observatory of Belgium in Uccle and a prolific discoverer of asteroids. The Minor Planet Center ranks him among the top 10 discoverers of minor planets with thousands of discoveries made at ESO's La Silla Observatory in northern Chile and at the Rozhen Observatory in Bulgaria during 19862009., 12838 Adamsmith , provisional designation 1997 EL55 , is a stony asteroid from the outer region of the asteroid belt , about 6 kilometers in diameter . It was discovered by Belgian astronomer Eric Walter Elst at ESO 's La Silla Observatory in northern Chile , on 9 March 1997 . The S - type asteroid is a member of the Koronis family , a group consisting of about 200 known bodies . It orbits the Sun at a distance of 2.7 -- 3.1 AU once every 4 years and 11 months ( 1,789 days ) . Its orbit is tilted by 1 degree to the plane of the ecliptic and shows an eccentricity of 0.06 . A photometric light - curve measurement at the Palomar Transient Factory Survey has rendered a rotation period of 10.9090 ± 0.0031 hours with a brightness amplitude of 0.48 in magnitude . The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 , a typical value for asteroids with a stony surface composition . The minor planet was named after Scottish moral philosopher Adam Smith ( 1723 -- 1790 ) , a key figure in the Scottish Enlightenment . He is known for his works The Theory of Moral Sentiments ( 1759 ) , and An Inquiry into the Nature and Causes of the Wealth of Nations ( 1776 ) . In the latter , he introduced the principle of the division of labor and suggested that self - interest is the only way to reach socially beneficial results ., Subject: 12838 adamsmith, Relation: site_of_astronomical_discovery, Options: (A) european southern observatory (B) harvard college observatory (C) la silla observatory (D) royal observatory (E) rozhen observatory
european southern observatory