Question: Who is a South Korean singer, Russ Ballard or Hyolyn?

Context paragraphs:
Russ Ballard: Russell Glyn Ballard (31 October 1945) is an English singer, songwriter and musician.

Hyolyn discography: The following is the discography of South Korean singer Hyolyn of the dance-pop girl group Sistar.  She has released one studio album, one extended play, and fourteen singles.  As of December 2016, Hyolyn has sold over 12 million digital records.

Hyolyn: Kim Hyo-jung (born January 11, 1991), better known by her stage name Hyolyn, is a South Korean singer-songwriter.  She is best known as a former member of South Korean girl group Sistar and their sub-unit Sistar19.

New York Groove: "New York Groove" is a song written by English singer/songwriter Russ Ballard, which was a hit for two different artists: the band Hello in 1975, and Ace Frehley in 1978.

Free Me (Roger Daltrey song): "Free Me" is a song written by Russ Ballard and performed by Roger Daltrey, singer for English rock band The Who.  The song is on Roger Daltrey's 1980 solo album "McVicar" and in the film "McVicar", also released in 1980.

Casanova (German band): Casanova was a German rock band formed by former members of the bands Mad Max, Bonfire, Warlock and the Rainbirds.  The band included singer Michael Voss and Michael Eurich, of Warlock (band), and recorded the songs of Russ Ballard.

Love &amp; Hate (Hyolyn album): Love & Hate is the debut solo album of Korean singer Hyolyn (leader of Sistar).  The album was released on November 26, 2013 and reached number 5 on South Korea's Gaon Album Chart.

It's Me (EP): It's Me is the first extended play by South Korean singer Hyolyn and second music release after her album "Love & Hate" in 2013.  The album was released on November 8, 2016 by Starship Entertainment and distributed by LOEN Entertainment.

Dream High 2: Dream High 2 (Korean: 드림하이 2 ) is a South Korean television drama series broadcast by KBS in 2012.  It stars Kang So-ra, GOT7's JB and Jinyoung, 2AM's Jinwoon, T-ara's Jiyeon, SISTAR's Hyolyn, and Park Seo-joon.  Like its prequel, it has 16 episodes which ran from January 30, 2012, until March 20 of the same year but was less successful, only averaging single-digit audience ratings.

Sunmin: Sunmin (Hangul: 선민, "Katakana": ソンミン, born August 4, 1987) is a South Korean singer who speaks and sings in Korean, Japanese, and English.  She debuted in 2006, with the single "Keep Holding You," a collaboration with the Japanese R&B singer Toshinobu Kubota.  Her career was initially focused on the Japanese market, but her work became focused in South Korea from 2009 to 2010.  She also contributed to original soundtracks of South Korean television series "Master of Study" and "Gloria (2010 TV series)".  In 2010 to 2011, she was in the main South Korean musical production of "Jekyll & Hyde" as Lucy.  In 2012 to 2013, she reprised her role as Lucy in the South Korean national tour.  In spring 2013, Sunmin played Josephine in the South Korean production of "Arsène Lupin", the musical.

Supporting paragraphs: Russ Ballard Hyolyn
Answer: Kim Hyo-jung