In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
One example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Question: Who believes Fagin's gang make wallets and handkerchiefs?
Solution is here: Oliver.
Explanation: In the sentence "He believes they make wallets and handkerchiefs", the pronoun "he" refers to name "Oliver".

Now, solve this: Passage: Ravel was not by inclination a teacher, but he gave lessons to a few young musicians he felt could benefit from them. Manuel Rosenthal was one, and records that Ravel was a very demanding teacher when he thought his pupil had talent. Like his own teacher, Faure, he was concerned that his pupils should find their own individual voices and not be excessively influenced by established masters. He warned Rosenthal that it was impossible to learn from studying Debussy's music: "Only Debussy could have written it and made it sound like only Debussy can sound." When George Gershwin asked him for lessons in the 1920s, Ravel, after serious consideration, refused, on the grounds that they "would probably cause him to write bad Ravel and lose his great gift of melody and spontaneity". The best known composer who studied with Ravel was probably Ralph Vaughan Williams, who was his pupil for three months in 190708. Vaughan Williams recalled that Ravel helped him escape from "the heavy contrapuntal Teutonic manner ... Complexe mais pas complique was his motto."Vaughan Williams's recollections throw some light on Ravel's private life, about which the latter's reserved and secretive personality has led to much speculation. Vaughan Williams, Rosenthal and Marguerite Long have all recorded that Ravel frequented brothels. Long attributed this to his self-consciousness about his diminutive stature, and consequent lack of confidence with women. By other accounts, none of them first-hand, Ravel was in love with Misia Edwards, or wanted to marry the violinist Helene Jourdan-Morhange. Rosenthal records and discounts contemporary speculation that Ravel, a lifelong bachelor, may have been homosexual. Such speculation recurred in a 2000 life of Ravel by Benjamin Ivry; subsequent studies have concluded that Ravel's sexuality and personal life remain a mystery.Ravel's first concert outside France was in 1909. As the guest of the Vaughan Williamses, he visited London, where he played for the Societe des Concerts Francais, gaining favourable reviews and enhancing his growing international reputation.
Question: What was the name of the person that warned Manuel Rosenthal about studying Debussy?
Solution:
Ravel.