Sweet Girl is the sixth mini-album released by B1A4 under WM Entertainment, the  title song of the album, "Sweet Girl", along with the other songs, was produced by which South Korean singer, songwriter, record producer, and actor?
Jung Jin-young
Jung Jin-young (singer)
Jung Jin-young (Hangul: 정진영 ; born November 18, 1991), professionally known as Jinyoung, is a South Korean singer, songwriter, record producer, and actor.
 He is the leader and vocalist of the South Korean boy group B1A4 under WM Entertainment, and has also gained recognition with the television series "Love in the Moonlight" (2016).
Sweet Girl (EP)
Sweet Girl is the sixth mini-album released by B1A4 under WM Entertainment.
 The album was released on August 10, 2015 by WM Entertainment and distributed by LOEN Entertainment.
 The title song of the album, "Sweet Girl", along with the other songs, was produced by leader Jinyoung.
 CNU also produced one song in the album called "Love is Magic".
 B1A4 won a trophy with "Sweet Girl" on the August 19 episode of MBC Every1 Show Champion and earned the title of the tenth most watched music video in America for August by Billboard.
WM Entertainment
WM Entertainment (Hangul: WM 엔터테인먼트) is a South Korean entertainment company established in 2008 by former singer (birth name: Kim Jung-soo).
 The company is responsible for managing artists such as B1A4 and Oh My Girl. Ignition (B1A4 album)
Ignition is the first full-length album released by B1A4 under WM Entertainment.
 The album was released on March 14, 2012 by WM Entertainment and their distributing label Pony Canyon Korea.
 The album spawned 2 singles namely "This Time Is Over" and "Baby I'm Sorry" which is the title track written and composed by the group's leader Jinyoung.
 A special edition of the album was released on May 24, 2012. Let's Fly
Let's Fly is the first mini-album released by B1A4 under WM Entertainment on April 21, 2011.
 The songs were mainly composed by Lee Sang-ho but Im Sanghyuk (Beast’s main songwriter) and Jeon Dawoon (K.Will’s main songwriter) have participated in the album along with all the members especially Jinyoung who was directly involved with the songwriting.
 All rap lyrics were written by Baro. Who Am I (B1A4 album)
Who Am I is the second full-length album released by B1A4 under WM Entertainment.
 The album was released on January 13, 2014 by WM Entertainment and their distributing label Pony Canyon Korea.
 The title song of the album, "Lonely (없구나), was produced by leader Jinyoung along with 7 other tracks in the album.
 CNU also took part in the composition with 2 self-produced songs. Good Timing
Good Timing is the third full-length album released by B1A4 under WM Entertainment.
 The album was released on November 28, 2016 by WM Entertainment and distributed by LOEN Entertainment.
 The first single, "A Lie (거짓말이야)", was produced by Jinyoung along with 9 other songs on the album.
 CNU also composed 3 songs. Oh My Girl (EP)
Oh My Girl is the debut extended play (EP) by South Korean girl group Oh My Girl.
 It was released by WM Entertainment on April 20, 2015 and distributed by LOEN Entertainment.
 The album was produced by Lee Won-min, CEO of WM Entertainment, with music produced by 72 and Moon Jeong-gyu.
 The album contains four songs, including the single "Cupid", which was released in conjunction with the album. It B1A4
It B1A4 is the second mini-album released by B1A4 and released by WM Entertainment released on September 16, 2011. Solo Day
Solo Day is the fifth mini-album released by B1A4 under WM Entertainment.
 The album was released on July 14, 2014 by WM Entertainment and their distributing label Pony Canyon Korea.
 The title song of the album, "Solo Day, was produced by leader Jinyoung along with 5 other tracks in the album.
 CNU also produced 1 song in the album.