Kwon Se-in (born June 29, 1982), better known as Kwon Yul actor.
 He made his acting debut with a leading role in the 2007 high school sitcom "Mackerel Run".
 Kwon is best known for his roles as Seo Ji-seok on the daily soap opera "Angel's Revenge" (2014), in the blockbuster period film "" (2014), and more recently as Lee Sang-woo in the hit romantic comedy series "Let's Eat 2" (2015).
 In 2017, Kwon starred in legal thriller drama "Whisper" alongside actress Lee Bo Young and Lee Sang-yoon.
School 2013 () is a 2012 South Korean television series starring Jang Nara, Choi Daniel, Lee Jong-suk and Kim Woo Bin.
 The teen drama depicts the struggles and dilemmas that modern-day Korean youth face, such as bullying, student suicides, school violence, deteriorating teacher-student relations, private tutoring and other real-life high school issues, all within the confines of one small classroom at Victory High School.
Doctor Stranger () is a 2014 South Korean television series starring Lee Jong-suk, Jin Se-yeon, Park Hae-jin and Kang So-ra.
 It aired on SBS from May 5 to July 8, 2014 on Mondays and Tuesdays at 21:55 for 20 episodes.
Martha Jones is a fictional character played by Freema Agyeman in the long-running British science fiction television series "Doctor Who" and its spin-off series, "Torchwood".
 She is a companion of the Tenth Doctor in "Doctor Who", after Rose Tyler (Billie Piper).
 According to the character's creator and executive producer Russell T Davies in his non-fiction book "", the character was developed from the beginning with the intention of appearing for a whole of the 2007 series, and to later make guest appearances in subsequent series and crossover appearances in the show's two spin-offs; Martha subsequently made guest appearances in "Torchwood" series two and in "Doctor Who" series four in 2008 and special episode "The End of Time" in 2010.
 Martha was also intended to make guest appearances in the 2009 series of "Torchwood" and "The Sarah Jane Adventures", but could not due to the actress's other obligations.
W () is a 2016 South Korean television series, starring Lee Jong-suk and Han Hyo-joo.
 It aired on Wednesdays and Thursdays at 22:00 (KST) on MBC from July 20 to September 14, 2016.
Pinocchio () is a 2014–2015 South Korean television series starring Lee Jong-suk, Park Shin-hye and Kim Young-kwang.
 It aired on SBS from November 12, 2014 to January 15, 2015 on Wednesdays and Thursdays at 21:55 (12:55 UTC) for 20 episodes.
Jin Se-yeon (born Kim Yoon-jung on February 15, 1994) is a South Korean actress.
 She played the female protagonist in the television dramas such as "My Daughter the Flower" (2011), "Bridal Mask" (2012), "Doctor Stranger" (2014), and "The Flower in Prison" (2016).
Nancy Borgenicht is an actress who starred in film and on television.
 She is best known for her role as Mrs. Randall in the 1984 horror movie "Silent Night, Deadly Night".
 She also appeared in "" (1988) as the woman attendant.
 Her other film roles include "Tripwire" (1989) and "Neon City" (1992).
 Nancy starred in the short lived 1990 television series "Teen Angel Returns" as Mrs. Henderson.
 She has appeared in some television movies like the 1986 TV movie "The Deliberate Stranger" (1986), and many others.
 She is also co-writer of the annual Salt Lake City production, Saturday's Voyeur, a parody of Utah politics and culture.
Lee Jong-suk (Hangul: 이종석, born 14 September 1989) is a South Korean actor and model.
 He debuted in 2005 as a runway model, becoming the youngest male model ever to participate in Seoul Fashion Week.
 Lee's breakout role was in "School 2013" (2012) and he is also well known for his roles in "I Can Hear Your Voice" (2013), "Doctor Stranger" (2014), "Pinocchio" (2014) and "W" (2016).
I Can Hear Your Voice () is a 2013 South Korean television series starring Lee Bo-young, Lee Jong-suk, Yoon Sang-hyun and Lee Da-hee.
 It aired on SBS from June 5 to August 1, 2013, on Wednesdays and Thursdays at 21:55 for 18 episodes.

Question: What is the nationality of actress Lee Jong-suk who starred in the Doctor Stranger television series?
Answer: South Korean