Question: In what sitcom did Karen Walker was a fictional character of?
Context: Taylor Walker is a fictional character from the American NBC soap opera, "Days of Our Lives", a long-running series about working-class life in the fictional town of Salem.  She was introduced in 1998 by head writer Sally Sussman Morina, and executive producer Ken Corday by actress Katherine Ellis.  The character was reintroduced in 2011, by former "General Hospital" actresses Natalia Livingston and Tamara Braun, the latter of whom also portrayed the character of Ava Vitali on the same show.  The character of Taylor Walker's last appearance was on September 22, 2011. Karen Walker ("née" Delaney; previously St. Croix, Popeil, and Finster) is a fictional character on the American television sitcom "Will & Grace", portrayed by Megan Mullally. Grace Elizabeth Adler (formerly Adler-Markus) is a fictional character in the American sitcom "Will & Grace", portrayed by Debra Messing.  A Jewish interior designer living in New York City, she lives with her gay best friend, Will Truman (played by Eric McCormack), for a majority of the series.  She is also the employer of Karen Walker (Megan Mullally) and the friend and neighbor of Jack McFarland (Sean Hayes). The Megan Mullally Show is an American talk show hosted by Megan Mullally that debuted in syndication on September 18, 2006, and was cancelled in January 2007 due to its low ratings.  Early promotions for the program featured Mullally as herself and as her "Will & Grace" character, Karen Walker.  The talk show also aired nationally on TBS and was distributed by NBCUniversal Television Distribution. William "Will" Truman is a fictional character on the American sitcom "Will & Grace", portrayed by Eric McCormack.  He is a lawyer who lives in the Upper West Side of New York City with his best friend, Grace Adler.  The series also portrays his relationship with the two other main characters, Karen Walker (Megan Mullally) and Jack McFarland (Sean Hayes). Karen MacKenzie (maiden name Cooper; formerly Fairgate) is a long-running fictional character in the CBS primetime soap opera "Knots Landing".  Karen is portrayed by actress Michele Lee, and has appeared on the show since its pilot episode, first broadcast on December 27, 1979.  "Knots Landing" follows the trials of four middle-class families living on a suburban cul-de-sac known as Seaview Circle in California.  Lee portrayed Karen for the entire run of "Knots Landing", being the sole cast member to appear in every episode of its fourteen seasons.  At the time, her appearances in all 344 episodes set a record for an actress on American primetime television.  Karen's storylines focus on family troubles, addiction and kidnapping.  In her early years on the serial, the character had much more of an "edge" in order to test the audience on who would be the most like J. R. Ewing (Larry Hagman), the primary character of its parent series "Dallas".  (The bad girl role would later be taken on by Abby Cunningham, Karen's sister-in-law.) Megan Mullally (born November 12, 1958) is an American actress and singer.  She is best known for her role as Karen Walker on the NBC sitcom "Will & Grace" (1998–2006, 2017-), for which she received 7 consecutive Primetime Emmy Award nominations for Outstanding Supporting Actress in a Comedy Series, winning twice in 2000 and 2006.  She also received nominations for numerous other accolades for her portrayal, including 7 consecutive Screen Actors Guild Awards nominations for Outstanding Performance by a Female Actor in a Comedy Series, winning 3 times in 2001, 2002, and 2003, as well as receiving 4 Golden Globe Award nominations. Karen McDonald (also Phillips) is a fictional character from the British ITV soap opera, "Coronation Street", played by Suranne Jones.  Karen was created by producer Jane Macnaught as a recurring character and one of the factory girls.  She made her debut in the episode airing on 21 June 2000.  On 13 May 2004, Jones announced her decision to leave the soap and her final scenes were broadcast on 26 December 2004.  Karen's storylines have focused on her number of boyfriends including, Vikram Desai (Chris Bisson) and Joe Carter (Jonathan Wrather), also her relationship with Steve McDonald (Simon Gregson) and her miscarriage and her feud with Tracy Barlow (Kate Ford), the mother of Steve's daughter. Rachel Karen Green is a fictional character, one of the six main characters who appeared in the American sitcom "Friends".  Portrayed by actress Jennifer Aniston, the character was created by show creators David Crane and Marta Kauffman, and appeared in each of the show’s 236 episodes during its decade-long run, from its premiere on September 22, 1994 to its finale on May 6, 2004.  Introduced in the show's pilot as a naive runaway bride who reunites with her childhood best friend Monica and relocates to New York City, Rachel gradually evolves from a spoiled, inexperienced daddy's girl into a successful businesswoman.  During the show's second season, the character becomes romantically involved with her friend Ross, with whom she maintains a complicated on-again, off-again relationship throughout the entire series.  Together, the characters have a daughter, Emma. Karen Spencer is a fictional character on the CBS soap opera, "The Bold and the Beautiful".  After Joanna Johnson's character Caroline Spencer Forrester was killed off the show, Karen was created to bring back Johnson to the Soap Opera.  She first appeared In 1991 and remained until 1994.  Johnson briefly returned to the role on April 28, 2009, and again in July 2011 for a several week brief story-arc.
Answer: Will & Grace