Question: Defendant, is a South Korean television series stars include Kwon Yu-ri, better known by the mononym Yuri, is a South Korean singer and actress, and debuted as a member of which girl group, in August 2007?
Context: Defendant () is a South Korean television series starring Ji Sung with Um Ki-joon, Kwon Yu-ri, Oh Chang-seok and Uhm Hyun-kyung.  It aired on SBS from January 23 to March 21, 2017 on Mondays and Tuesdays at 22:00 (KST) for 18 episodes. Kwon Min-ah (born September 21, 1993), better known by the mononym Mina, is a South Korean singer and actress.  She is best known as a member of the girl group AOA.  Mina has acted in television dramas, including "Modern Farmer" (2014) and "All About My Mom" (2015). Im Yoon-ah (Hangul: 임윤아 ; born May 30, 1990), better known by the mononym Yoona, is a South Korean singer and actress.  She debuted as a member of girl group Girls' Generation in August 2007, who went on to become one of the best-selling artists in South Korea and one of South Korea's most popular girl groups worldwide. Tiffany Hwang (born Stephanie Young Hwang, better known by the mononym Tiffany) is a South Korea-based American singer.  Her discography consists of one extended play, ten singles (including eight as featured artist), and twelve soundtrack appearances.  She debuted as a member of South Korean girl group Girls' Generation under S.M. Entertainment in August 2007 and has since achieved immense popularity on the Asian music scene.  Tiffany is also a member of the Girls' Generation subgroup TTS and has recorded tracks for soundtracks for various television drama series and films. Kim Hyo-yeon (born September 22, 1989), better known mononymously as Hyoyeon, is a South Korean singer and television personality.  She debuted as a member of girl group Girls' Generation in August 2007, who went on to be one of the best-selling artists in South Korea and one of South Korea's most popular girl groups worldwide. Kwon Yu-ri (born December 5, 1989), better known by the mononym Yuri, is a South Korean singer and actress.  She debuted as a member of girl group Girls' Generation in August 2007, who went on to be one of the best-selling artists in South Korea and one of South Korea's most popular girl groups worldwide.  Apart from her group's activities, she has been in several television dramas such as "Fashion King" (2012), "Neighborhood Hero" (2016), the web drama "Gogh, The Starry Night" and "Defendant" (2017).  In 2013, she made her film debut in "No Breathing". Kim Chung-ha (born Kim Chan-mi on February 9, 1996), better known by the mononym Chungha, is a South Korean singer.  She is best known for finishing fourth in Mnet's girl group survival show "Produce 101" and as a former member of the now disbanded South Korean girl group I.O.I. Kim Tae-yeon, better known by the mononym Taeyeon, is a South Korean singer.  Her discography consists of one studio album, two extended plays (EPs), twenty singles (including four as featured artist), and three promotional singles.  She debuted as a member of South Korean girl group Girls' Generation in August 2007 and initially gained some popularity as a singer upon recording soundtrack songs "If" for "Hong Gil Dong" and "Can You Hear Me" for "Beethoven Virus" (2008).  She subsequently established herself as one of the most renowned vocalist on the South Korean music scene with further soundtrack recordings, notably "I Love You" for "" (2010), "Missing You like Crazy" for "The King 2 Hearts", "Closer" for "To the Beautiful You" (2012), and "And One" for "That Winter, the Wind Blows" (2013), all of which managed to enter the top ten of South Korea's Gaon Digital Chart.  Apart from soundtrack recordings, Taeyeon has also recorded duets with other artists, most notably "Like a Star" with The One and "Different" with Kim Bum-soo, which peaked at numbers one and two on the Gaon Digital Chart, respectively. Seo Ju-hyun (born June 28, 1991), known professionally as Seohyun, is a South Korean singer and actress.  She debuted as a member of girl group Girls' Generation (and later its subgroup TTS) in August 2007, who went on to be one of the best-selling artists in South Korea and one of South Korea's most popular girl groups worldwide.  Apart from her group's activities, she has established herself as an actress, notably through her participation in the original and Korean versions of stage musicals including "Moon Embracing the Sun", "Gone with the Wind" and "Mamma Mia".  She also starred in the drama "".  She debuted as a solo artist with her debut mini album, "Don't Say No", on January 17, 2017, making her the third Girls' Generation member to debut as a solo artist. Kwon So-hyun (born August 30, 1994), is a South Korean singer and actress.  She was known as a member of the South Korean girl group 4Minute, under Cube Entertainment.  She is also a former member of the South Korean girl group, Orange.  Before June 15, 2016 (end of her contract with Cube), Sohyun left 4Minute and the record label along with members Nam Ji-hyun, Heo Ga-yoon, and Jeon Ji-yoon.
Answer: Girls' Generation