premise: Seohyun sings.
hypothesis: Do n't Say No is the debut extended play by South Korean singer Seohyun . Seo Ju-hyun ( born June 28 , 1991 ) , known professionally as Seohyun , is a South Korean singer and actress . She debuted as a solo artist with her debut mini album , Do n't Say No , on January 17 , 2017 , making her the third Girls ' Generation member to debut as a solo artist . Seohyun ( born Seo Joo-hyun ) is a South Korean singer , member of Girls ' Generation and its subgroup Girls ' Generation-TTS .