input question: Given the following context:  William "Bill" Boss, a psychopathic prison warden, watches the end of The Human Centipede 2 (Full Sequence) with his accountant, Dwight Butler. Bill says that he hates the films as his feet are massaged by his secretary, Daisy. Daisy replies that she enjoyed them. In response, Bill sucks his finger and inserts it into Daisy's vagina, telling her that women should not be allowed to voice their opinions. Dwight interrupts, attempting to pitch a "brilliant idea" to fix the prison's horrible retention and violence rates, but he is interrupted by a phone call. Bill and Dwight are then summoned to the scene of an assault within the prison. One of the officers has been stabbed by an inmate. As punishment, Bill decides to stomp on the arm of the prisoner, exposing the bone and causing immense pain. He promises to do it again when his bones are healed. Back in the Warden's office, Bill receives a mysterious package. After Dwight asks what it contains, Bill reveals that it is a jar of specially imported, dried African clitorises which he eats "for strength." After eating a few, he receives a threatening prank phone call from one of the inmates. Bill waterboards him with three buckets of boiling water, horribly disfiguring him. The inmate tells Bill that he has lost his soul. Governor Hughes arrives immediately afterwards, ordering Bill and Dwight to put a stop to the violence and promising that they will both be fired otherwise. In anger and retaliation, Bill orders a 'mass castration' of the inmates, and castrates one of the prisoners himself. He covers his face in the blood of the inmate and later eats the cooked testicles for lunch, calling it "Energy Food." Daisy is forced to perform fellatio on Bill while Dwight is in the room. Upon completing the act, Daisy eats one of the dried clitorises, mistaking them for candy.  answer the following question:  What is the last name of the person who breaks someone's arm????
output answer: Boss

Given the following context:  Yellowstone National Park is an American national park located in Wyoming, Montana, and Idaho.  It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the U.S. and is also widely held to be the first national park in the world. The park is known for its wildlife and its many geothermal features, especially Old Faithful geyser, one of its most popular features. It has many types of ecosystems, but the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion. Native Americans have lived in the Yellowstone region for at least 11,000 years. Aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park originally fell under the jurisdiction of the Secretary of the Interior, the first being Columbus Delano. However, the U.S. Army was subsequently commissioned to oversee management of Yellowstone for a 30-year period between 1886 and 1916. In 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, and researchers have examined more than a thousand archaeological sites. Yellowstone National Park spans an area of 3,468.4 square miles (8,983 km2), comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years. Half of the world's geysers and hydrothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of...  answer the following question:  What four things is Yellowstone comprised of?
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Answer: lakes

Problem: Given the question: Given the following context:  In the year 2023 in a dystopian future, Sentinels have been programmed to identify and hunt down mutants and any humans who dared to help them. A small band of X-Men survivors is attacked, and Kitty Pryde sends Bishop's consciousness back in time a few days before the attack, to warn the others as to ensure their survival. The group later meets Professor Charles Xavier at a remote Chinese temple, where he explains the history of the Sentinels, which were designed by Bolivar Trask, whom Mystique assassinated in 1973. Alarmed by Trask's death, the government forces captured Mystique and experimented on her, using her DNA to advance the Sentinel program, thus allowing them to adapt to nearly every mutant power. Xavier and Magneto plan to use Pryde's ability to prevent Trask's assassination and prevent the apocalyptic future. But since Xavier would not survive going back decades, Wolverine volunteers, since his regenerative powers would allow him to survive the process. After awakening in his younger body in 1973, Wolverine arrives at the X-Mansion, discovering that the school has been shut down for years due to many students and staff being drafted to the Vietnam War, and that Erik Lensherr was arrested for killing John F. Kennedy. A young, broken Xavier turned to alcoholism and has shunned his mutant powers by using a specialized serum that suppresses his telepathic abilities in order to walk. Hoping to reunite with Mystique, Xavier agrees to help Wolverine and breaks Lensherr out of his prison cell under the Pentagon, aided by Hank McCoy and Peter Maximoff.  answer the following question:  What is the last name of the person who explains the history of the Sentinels?
++++++++++++++++++++++++++++++++
The answer is:
Xavier