Question: Who was the winner of dancing with the stars season 21?

Disambiguated questions and answers:
context: No context provided
question: Who won "Dancing with the Stars" in season 21?
short_answers: Derek Hough

Bindi Irwin

context: On November 24, 2015, Bindi Irwin and her partner Derek Hough were crowned champions. Nick Carter and Sharna Burgess finished second, Alek Skarlatos and Lindsay Arnold placed third. This season set records for the total number of perfect scores awarded (23) and the number of stars to receive at least one perfect score with 7 (Bindi Irwin, Nick Carter, Alek Skarlatos, Carlos PenaVega, Tamar Braxton, Alexa PenaVega, and Andy Grammer). Irwin also set a record with 8 perfect scores (a record broken in season 25 by Jordan Fisher) and became the second youngest winner of the show at 17 years old (after season 8 winner Shawn Johnson, who was 3 days younger at the time of her win, and later slipped to third behind season 23 winner Laurie Hernandez, who was 16 years old at the time of her win). This also marked Hough's sixth competitive win, extending his own record for the most wins for a professional dancer on the series.
question: Who won "Dancing with the Stars" in 2015?
short_answers: Derek Hough

Bindi Irwin
wikipage: Dancing with the Stars (American season 21)

context: On August 19, 2015, nine professional dancers were revealed during "Good Morning America". Karina Smirnoff, who did not appear in season 20 returned for season 21. Anna Trebunskaya and Louis van Amstel would be returning after a five-season hiatus. Additionally, Lindsay Arnold would also be returning after spending the last four seasons in the troupe. While Peta Murgatroyd (who was to be paired with Andy Grammer) was originally announced as a professional, was sidelined for the season by an ankle injury, Allison Holker replaced her spot in the cast; Artem Chigvintsev and Kym Johnson also did not return. Bindi Irwin was the first celebrity revealed on August 24, on "GMA"; other celebrities were revealed at different dates through different media. The full cast of celebrities and professional dancers was revealed on September 2, 2015, on "GMA."
question: Who was the celebrity winner of dancing with the stars, season 21?
short_answers: Bindi Irwin
wikipage: Dancing with the Stars (American season 21)

context: On November 24, 2015, Bindi Irwin and her partner Derek Hough were crowned champions. Nick Carter and Sharna Burgess finished second, Alek Skarlatos and Lindsay Arnold placed third. This season set records for the total number of perfect scores awarded (23) and the number of stars to receive at least one perfect score with 7 (Bindi Irwin, Nick Carter, Alek Skarlatos, Carlos PenaVega, Tamar Braxton, Alexa PenaVega, and Andy Grammer). Irwin also set a record with 8 perfect scores (a record broken in season 25 by Jordan Fisher) and became the second youngest winner of the show at 17 years old (after season 8 winner Shawn Johnson, who was 3 days younger at the time of her win, and later slipped to third behind season 23 winner Laurie Hernandez, who was 16 years old at the time of her win). This also marked Hough's sixth competitive win, extending his own record for the most wins for a professional dancer on the series.
question: Who was the Pro winner of dancing with the stars, season 21?
short_answers: Derek Hough
wikipage: Dancing with the Stars (American season 21)

context: On November 24, 2015, Bindi Irwin and her partner Derek Hough were crowned champions. Nick Carter and Sharna Burgess finished second, Alek Skarlatos and Lindsay Arnold placed third. This season set records for the total number of perfect scores awarded (23) and the number of stars to receive at least one perfect score with 7 (Bindi Irwin, Nick Carter, Alek Skarlatos, Carlos PenaVega, Tamar Braxton, Alexa PenaVega, and Andy Grammer). Irwin also set a record with 8 perfect scores (a record broken in season 25 by Jordan Fisher) and became the second youngest winner of the show at 17 years old (after season 8 winner Shawn Johnson, who was 3 days younger at the time of her win, and later slipped to third behind season 23 winner Laurie Hernandez, who was 16 years old at the time of her win). This also marked Hough's sixth competitive win, extending his own record for the most wins for a professional dancer on the series.
question: Who was the professional winner of dancing with the stars season 21?
short_answers: Derek Hough
wikipage: Dancing with the Stars (American season 21)

context: On August 19, 2015, nine professional dancers were revealed during "Good Morning America". Karina Smirnoff, who did not appear in season 20 returned for season 21. Anna Trebunskaya and Louis van Amstel would be returning after a five-season hiatus. Additionally, Lindsay Arnold would also be returning after spending the last four seasons in the troupe. While Peta Murgatroyd (who was to be paired with Andy Grammer) was originally announced as a professional, was sidelined for the season by an ankle injury, Allison Holker replaced her spot in the cast; Artem Chigvintsev and Kym Johnson also did not return. Bindi Irwin was the first celebrity revealed on August 24, on "GMA"; other celebrities were revealed at different dates through different media. The full cast of celebrities and professional dancers was revealed on September 2, 2015, on "GMA."
question: Who was the celebrity winner of dancing with the stars season 21?
short_answers: Bindi Irwin

Bindi Sue Irwin
wikipage: Dancing with the Stars (American season 21)

Long answers:
knowledge: content: Season twenty-one of the American television competition series Dancing with the Stars premiered on September 14, 2015.
wikipage: Dancing with the Stars (American season 21)
long_answer: The winner of season 21 of the television show, "Dancing with the Stars", was Derek Hough and Bindi Irwin. Derek Hough is a professional dancer and Bindi Sue Irwin is a celebrity who won the season in 2015. 

knowledge: content: Dancing with the Stars is an American dance competition television series that premiered on June 1, 2005, on ABC.
wikipage: Dancing with the Stars (American TV series)

content: Season twenty-one of the American television competition series Dancing with the Stars premiered on September 14, 2015.
wikipage: Dancing with the Stars (American season 21)

content: Bindi Sue Irwin[1] (born 24 July 1998)[2] is an Australian television personality, conservationist, zookeeper, and actress.[3][4][5]
wikipage: Bindi Irwin

content: Derek Bruce Hough (/ˈhʌf/; born May 17, 1985[1]) is an American professional Latin and ballroom dancer, choreographer, actor and singer.[2][3]
wikipage: Derek Hough

content: On November 24, 2015, Bindi Irwin and her partner Derek Hough were crowned champions.
wikipage: Dancing with the Stars (American season 21)
long_answer: Dancing with the Stars is an American dance competition television series that premiered on June 1, 2005, on ABC. Season twenty-one premiered on September 14, 2015. Bindi Irwin, an Australian television personality, conservationist, zookeeper, and actress, and her partner Derek Hough, an American professional Latin and ballroom dancer, choreographer, actor and singer, were crowned champions.