Given the question: Information:  - A book is a set of written, printed, illustrated, or blank sheets, made of paper, parchment, or other materials, fastened together to hinge at one side, with text and/or images printed in ink. A single sheet within a book is a leaf, and each side of a leaf is a page. A set of text-filled or illustrated pages produced in electronic format is known as an electronic book, or e-book.   - The Mystery of the Silver Spider is a book in the Three Investigators series . In this episode , the Three Investigators almost run into Prince Djaro with their car . Djaro is the soon to be prince of the fictional European state of Varania , a country which is still very conscious of old traditions and fashions ( around the 17th to 19th century ) . They form an instant friendship with him . Soon afterwards , they are asked by the United States Secret Service to travel to Varania to keep an eye on Djaro ; there are rumors and indications that Djaro is to be dethroned . An important role in the plot is played by the title 's Silver Spider , a piece of jewelry which is the most treasured item of Varanian history ( comparable to the English Crown Jewels ) . Soon , the Investigators find themselves actively involved , as the conspirators -- headed by Duke Stefan , an ambitious nobleman and interim ruler of Varania -- attempt to frame them for stealing the Spider , and by implication sully the name of Prince Djaro and endanger his coronation . Djaro can not be crowned unless he is wearing the Silver Spider around his neck . Stefan and his men have stolen the real Silver Spider and left an imitation in its place . Bob suffers amnesia in their subsequent flight , and the Silver Spider goes missing . The Three Investigators and a pair of Djaro loyalists hide out , while scheming to expose Stefan 's plot and help Djaro to prevail . Despite the fact that all seems hopeless , they finally prevail when Jupe recalls an important piece of Varanian history , which allows them to alert and rally Varania 's loyal citizenry . The effort is wrapped up when Jupiter finds the Silver Spider as `` nothing more than a spider '' , hidden ingeniously by Bob in a real spider 's web .  - Bertelsmann is a German multinational corporation based in Gütersloh, North Rhine-Westphalia, Germany. It is one of the world's largest mass media companies and also active in the service sector and education. Bertelsmann was founded as a publishing house by Carl Bertelsmann in 1835. After World War II, Bertelsmann, under the leadership of Reinhard Mohn, went from being a medium-sized enterprise to a major conglomerate, offering not only books but also television, radio, magazines and business services. Bertelsmann is an unlisted and capital market-oriented company, which remains primarily controlled by the Mohn family. Since 2016, major divisions of Bertelsmann are RTL Group, Penguin Random House, Gruner + Jahr, BMG, Arvato, Bertelsmann Printing Group, Bertelsmann Education Group and Bertelsmann Investments.  - The Three Investigators is an American juvenile detective book series first published as ""Alfred Hitchcock and the Three Investigators"". It was created by Robert Arthur Jr., who believed using a famous person such as movie director Hitchcock would attract attention. Random House, which is owned by Bertelsmann, is the U.S. publisher and still has some of the rights to the books. Other rights are possessed by the heirs of Robert Arthur, Jr. and the German publisher Kosmos. The characters known as the "three investigators" are three boys named Jupiter Jones, Peter Crenshaw and Bob Andrews.    Given the information above, choose from the list below the object entity that exhibits the relation 'author' with the subject 'the mystery of the silver spider'.  Choices: - alfred hitchcock  - one  - robert arthur
The answer is:
robert arthur