Robert Dale "Rob" McElhenney (born April 14, 1977) is an American actor, director, producer, and screenwriter.
 He is best known for playing Mac on the FX/FXX comedy series "It's Always Sunny in Philadelphia".
 He is also one of the developers, executive producers, and the creator of the show, which has provided him with writing and directing credits on various episodes.
Glenn Franklin Howerton III (born April 13, 1976) is an American actor, producer, and screenwriter.
 He is known for his role as Dennis Reynolds in "It's Always Sunny in Philadelphia", for which he is also a writer and executive producer.
The Mick is an American sitcom television series broadcast on Fox.
 Created by Dave Chernin and John Chernin, the series stars Kaitlin Olson, who is also an executive producer.
 The series premiered on January 1, 2017, and resumed in its regular Tuesday night slot on January 3, 2017.
 On January 11, 2017, Fox picked up the series for a full season of 17 episodes.
Becky Mann is a television producer and screenplay writer, best known for her role as a writer in "It's Always Sunny in Philadelphia" and producer of "Rules of Engagement".
It's Always Sunny in Philadelphia is an American television black comedy sitcom that premiered on FX on August 4, 2005.
 It moved to FXX beginning with the ninth season, and has remained there since.
 It was created by Rob McElhenney, who developed it with Glenn Howerton.
 It is executive produced and primarily written by McElhenney, Howerton, and Charlie Day, all of whom star alongside Kaitlin Olson and Danny DeVito.
 The series follows the exploits of "The Gang", a group of debauched self-centered friends who run the Irish bar Paddy's Pub in South Philadelphia.
Kaitlin Willow Olson (born August 18, 1975) is an American actress and comedian.
 She began her career in the Groundlings, an improvisational group in Los Angeles, California, and had minor roles in several television series before being cast as Deandra "Sweet Dee" Reynolds on the FX black comedy series "It's Always Sunny in Philadelphia" in 2005.
Robert "Bob" Towers (born August 19, 1936) is an American actor and voice actor, who has appeared in many television shows, including "".
 He also played Buster the coke snorting Jockey on "It's Always Sunny In Philadelphia" on season 3 episode "The Gang Gets Whacked".
 He played the teenage Benjamin in the feature film, The Curious Case of Benjamin Button.
Boldly Going Nowhere was a proposed American television show for Fox.
 Rob McElhenney, Glenn Howerton, and Charlie Day, the producers and stars of "It's Always Sunny in Philadelphia", created the show along with their "Always Sunny" writers' assistant Adam Stein.
 While they did not plan to star in the show, they were the executive producers.
Sianoa Smit-McPhee (born 21 February 1992), also known as Sianoa, is an Australian singer, songwriter and actress.
 She is best known for her years in Australian soap opera "Neighbours" as Bree Timmins.
 Her next role was in the children's television series "As the Bell Rings", which aired on the Disney Channel.
 In 2007, she appeared as Desma, the lead character in the short fantasy film "Hugo".
 From 2009 to 2011, she starred in the HBO series "Hung" as Darby Drecker.
 In 2012, Sianoa featured in the TV movie ABC "Firelight" and the series "It's Always Sunny in Philadelphia".
 The following year, she starred in "All Cheerleaders Die".
 Sianoa and her husband John Rush, a music producer, also wrote and produced the song "Take a Bite of My Heart", which was featured in the film and performed by Sianoa.
The Waitress is a fictional character on the FX, now FXX series, "It's Always Sunny in Philadelphia", and is portrayed by Mary Elizabeth Ellis.
 The Waitress is a waitress at a Philadelphia coffee shop who is frequently stalked by an enamored Charlie Kelly.
 The Waitress's real name is never revealed and no one in the gang can remember it despite knowing her for several years.

Question: Which executive producer also played Deandra Reynold in "It's Always Sunny in Philadelphia?"
Answer: Kaitlin Olson