Question: Girls' Generation-TTS (, also known as TTS, TaeTiSeo, or Girls' Generation-TaeTiSeo) is a subgroup of South Korean girl group Girls' Generation, formed by S.M. Entertainment in 2012, is composed of three Girls' Generation members: Taeyeon, Tiffany, and which South Korean singer and actress, known professionally as Seohyun, born in which year ?
Sentence (from "Seohyun"): 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".
Relevant evidence: No