Question: Which HBO series features an actor who made a movie in 1981 with George A. Romero?

Context paragraphs:
Survival of the Dead: Survival of the Dead (also known as George A. Romero's Survival of the Dead) is a 2009 American horror film written and directed by George A. Romero and starring Alan van Sprang, Kenneth Welsh and Kathleen Munroe.  It is the sixth entry in Romero's "Night of the Living Dead" series.  The story follows a group of AWOL National Guardsmen who briefly appeared in "Diary of the Dead".

John Amplas: John Amplas (born June 23, 1949 in Pittsburgh, Pennsylvania) is an American actor known primarily for his work with director George A. Romero.  His first work with Romero was the cult film "Martin" (1978), in which he played the title role.  Thereafter, he has appeared in a number of other films directed by Romero, including "Dawn of the Dead" (1978), "Knightriders" (1981), "Creepshow" (1982), and "Day of the Dead" (1985), as well as "Toxic Zombies" (1980), a former video nasty, and "Midnight" (1982), directed by John Russo.  He has recently acted in a horror concept teaser entitled "The Three" (2011) directed by filmmaker Scott Goldberg which also features co-lead from "Day of the Dead" Lori Cardille.  He starred also in the feature film adaption of the Rob Steigert short film "Ombis".

Knightriders: Knightriders, also known as George A. Romero's Knightriders, is a 1981 American drama film written and directed by George A. Romero and starring Ed Harris, Gary Lahti, Tom Savini, Amy Ingersoll, Patricia Tallman and Ken Foree.  It was filmed entirely on location in the Pittsburgh metro area, with major scenes in suburban Fawn Township and Natrona.

Dawn of the Dead (1978 film): Dawn of the Dead (also known internationally as Zombi) is a 1978 American independent zombie horror film directed by George A. Romero.  It was written by Romero in collaboration with the Italian filmmaker Dario Argento and produced by Richard P. Rubinstein.  It was the second film made in Romero's "Living Dead" series and shows in a larger scale the apocalyptic effects on society, though it contains no characters or settings from "Night of the Living Dead".  In the film, a phenomenon of unidentified origin has caused the reanimation of the dead, who prey on human flesh.  David Emge, Ken Foree, Scott Reiniger, and Gaylen Ross star as survivors of the outbreak who barricade themselves inside a suburban shopping mall amid mass hysteria.

Ed Harris: Edward Allen Harris (born November 28, 1950) is an American actor, producer, director, and screenwriter.  He is known for his performances in films such as "The Right Stuff" (1983), "The Abyss" (1989), "Glengarry Glen Ross" (1992), "Apollo 13" (1995), "Nixon" (1995), "The Rock" (1996), "Absolute Power" (1997), "A Beautiful Mind" (2001), "Enemy at the Gates" (2001), "Radio" (2003), "A History of Violence" (2005), "Gone Baby Gone" (2007), "The Way Back" (2010), "Man on a Ledge" (2012), "Gravity" (2013), "Snowpiercer" (2013), and "Run All Night" (2015).  Harris currently stars in the HBO sci-fi drama series "Westworld".

Night of the Living Dead (film series): The Dead is a series of six zombie horror films created by George A. Romero beginning with the 1968 film "Night of the Living Dead" directed by Romero who co-written with John A. Russo.  The loosely connected franchise predominantly centers on different groups of people attempting to survive during the outbreak and evolution of a zombie apocalypse.  The latest installment of the series, "Survival of the Dead", was released in 2009, with "Origins", a prequel film written and directed by Cameron Romero (son of George) in the works.

Philip Marlowe, Private Eye: Philip Marlowe, Private Eye is an American mystery series that aired on HBO in the United States from April 16, 1983 through June 3, 1986, and on ITV in the United Kingdom.  The series features Powers Boothe as Raymond Chandler's title character, and was the first drama produced for HBO.  It was an early example of the uncompromising commitment to authenticity HBO would become known for in period pieces, recently showcased in "Rome" and "Deadwood", the latter of which also featured actor Powers Boothe.  Unlike other modern incarnations of the Marlowe character, the HBO series kept the show set in the 1930s, true to the original Raymond Chandler stories.

Ectoplasm (radio show): Ectoplasm was a 2000 BBC Radio 4 comedy series written by and starring Dan Freedman and Nick Romero.  Unlike the other radio work of Freedman and Romero, this series features single, coherent stories in each episode; certain motifs do, however, appear in all of the tales, e.g. Theremin's murder attempts.

Jeffrey Wright: Jeffrey Wright (born December 7, 1965) is an American film, television and stage actor.  He is known for such roles as Belize in the HBO miniseries "Angels in America", Jean-Michel Basquiat in "Basquiat", Felix Leiter in the James Bond films "Casino Royale" and "Quantum of Solace", Valentin Narcisse in the HBO series "Boardwalk Empire", and Beetee in "The Hunger Games" films.  He currently stars as Bernard Lowe in the HBO series "Westworld".

Def Poetry Jam: Russell Simmons presents Def Poetry, better known as simply Def Poetry Jam or Def Poetry, was a spoken word poetry television series hosted by Mos Def and airing on HBO between 2002 and 2007.  The series features performances by established and up-and-coming spoken word poets.  Performances also include special appearances by well-known actors and musicians, as well as occasional performances by Mos Def himself.  Co-created by Bruce George, Danny Simmons, Deborah Pointer, Stan Lathan, and Russell Simmons, the show is a spin-off of the popular "Def Comedy Jam" which began airing on HBO in the 90's.  As with "Def Comedy", Simmons appears at the end of every episode to thank the audience.

Supporting paragraphs: Knightriders Ed Harris
Answer: Westworld