This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Input: Consider Input: Passage: In September 1828 Chopin, while still a student, visited Berlin with a family friend, zoologist Feliks Jarocki, enjoying operas directed by Gaspare Spontini and attending concerts by Carl Friedrich Zelter, Felix Mendelssohn and other celebrities. On an 1829 return trip to Berlin, he was a guest of Prince Antoni Radziwi, governor of the Grand Duchy of Posenhimself an accomplished composer and aspiring cellist. For the prince and his pianist daughter Wanda, he composed his Introduction and Polonaise brillante in C major for cello and piano, Op. 3. Question: What piece did Frederic create specifically for the prince and the prince's daughter, Wanda?

Output: Introduction and Polonaise brillante in C major for cello and piano, Op. 3

Input: Consider Input: Passage: During the administration of U.S. President Martin Van Buren, nearly 17,000 Cherokeesalong with approximately 2,000 black slaves owned by Cherokeeswere uprooted from their homes between 1838 and 1839 and were forced by the U.S. military to march from "emigration depots" in Eastern Tennessee (such as Fort Cass) toward the more distant Indian Territory west of Arkansas. During this relocation an estimated 4,000 Cherokees died along the way west. In the Cherokee language, the event is called Nunna daul Isunyi"the Trail Where We Cried." The Cherokees were not the only American Indians forced to emigrate as a result of the Indian removal efforts of the United States, and so the phrase "Trail of Tears" is sometimes used to refer to similar events endured by other American Indian peoples, especially among the "Five Civilized Tribes". The phrase originated as a description of the earlier emigration of the Choctaw nation. Question: How many Cherokee-owned black slaves were also relocated between 1838 and 1839?

Output: 2,000

Input: Consider Input: Passage: Delicate sounds and fine overtones were mostly lost, because it took a lot of sound energy to vibrate the recording horn diaphragm and cutting mechanism. There were acoustic limitations due to mechanical resonances in both the recording and playback system. Some pictures of acoustic recording sessions show horns wrapped with tape to help mute these resonances. Even an acoustic recording played back electrically on modern equipment sounds like it was recorded through a horn, notwithstanding a reduction in distortion because of the modern playback. Toward the end of the acoustic era, there were many fine examples of recordings made with horns. Question: Why do photos show take on horns?
Output: help mute these resonances