Question: Which American film director, producer, screenwriter co-founded Troma Entertainment film studio, Lloyd Kaufman or Joseph Ruben?

Context paragraphs:
Joseph Ruben: Joseph Porter Ruben (born May 10, 1950) is an American film director, screenwriter and producer.

Pat Swinney Kaufman: Patricia Swinney Kaufman (born 1950) is the executive director of the New York State Governor's Office for Motion Picture and Television Development and the deputy commissioner of Empire State Development.  Kaufman is the former president of the Association of Film Commissioners International, where she still serves on the board of directors.  She is the secretary for the Hamptons International Film Festival and has also acted in some films directed by her husband, Lloyd Kaufman, the co-founder of Troma Entertainment.

The First Turn-On!: The First Turn-On!  is a 1983 comedy film directed by Lloyd Kaufman and Michael Herz of Troma Entertainment.  It was the last in a series of four "sexy comedies" that helped establish Troma as a film studio, starting with 1979's "Squeeze Play! ", 1981's "Waitress! " and 1982's "Stuck on You! ".

Terror Firmer: Terror Firmer is a 1999 American comedy horror film directed by Lloyd Kaufman, written by Douglas Buck, Patrick Cassidy, Kaufman, and James Gunn, and starring Will Keenan, Alyce LaTourelle, and Kaufman.  The film was produced by the Troma Entertainment company, known for distributing campy exploitation films.

List of Troma Team Video Titles: Troma Entertainment was founded out of the rubble of Lloyd Kaufman’s Armor Films in 1974 as a production company.  In 1995, Kaufman and vice president Michael Herz formed Troma Team Video who would handle all of their distribution instead of going through a third company.  Since 1995, they have been releasing Troma titles (including titles the company has bought since being formed and a mighty collection of older classics with The Roan Group) on DVD and virally.  They started re-releasing their films on Blu-ray in 2010.

Lloyd Kaufman: Stanley Lloyd Kaufman, Jr. (born December 30, 1945) is an American film director, producer, screenwriter, and actor.  With producer Michael Herz, he is the co-founder of Troma Entertainment film studio, and the director of many of their feature films, including "The Toxic Avenger" and "Tromeo and Juliet".

I Was a Teenage TV Terrorist: I Was a Teenage TV Terrorist (also known as Amateur Hour) is a 1985 comedy film directed by Stanford Singer and distributed by Troma Entertainment.  The film follows two bored teenagers, anarchic troublemaker Paul and aspiring actress Donna, as they use Paul's father's TV station to stage an elaborate bomb hoax and throw the media into a frenzy.  The film was produced by Susan Kaufman, the sister of Lloyd Kaufman, the president of Troma Entertainment.

When Nature Calls: When Nature Calls is a 1985 spoof comedy written and directed by Charles Kaufman and starring Academy Award nominee David Strathairn in an early performance.  The film was distributed by Charles Kaufman's brother, Lloyd Kaufman, of Troma Entertainment (sister Susan Kaufman worked as an art director and their father Stanley appeared as an actor in the film).

Aiden Dillard: Aiden Dillard is an American independent film director and artist.  He is known for using surreal humor and camp (style) within the confines of low-budget film.  Aiden Dillard was born in Escondido, California, but grew up in Durham, North Carolina.  Aiden Dillard's feature films and video art often deals with contrasts between a rural and urban area, and high culture and low culture.  While studying at Cooper Union in New York City on a full-tuition scholarship, his student film "The Battle of the Burps and Farts" was screened at TromaDance 2004 and was the only film in the history of the festival that was booed by everybody in attendance.  Upon graduation Aiden Dillard directed an outrageous psychedelic spoof of "Reefer Madness", titled "Meat Weed Madness", which featured set decoration by Joe Holtzman, the editor-in-chief of Nest (magazine), and crudely constructed props and stop-motion animation. " Meat Weed Madness" premièred at the Wolfsonian-FIU in December 2005 during Art Basel Miami Beach, and was released on DVD by Troma Entertainment in 2006.  Aiden Dillard's even more outrageous sequel "Meat Weed America" was released by Troma Entertainment on DVD in the fall of 2007, and features Troma's president Lloyd Kaufman, Debbie Rochon, and Peter Stickles.  In 2008, Aiden Dillard moved to Miami, and wrote, produced, and directed a psychedelic crime-drama about children with autism who see angels called "Special Angelz", which premiered at Borscht Film Festival.  In 2009, Aiden Dillard wrote, produced, and directed an action-comedy spoof of "Death Wish" called "Death Print", which was set in the Miami art-world and shows an art dealer, played by Ted Vernon, who battles a Cuban Communist terrorist, with the help of musician Otto Von Schirach.  This movie had a sold out premiere at the Colony Theatre in South Beach.  From 2010-2012 Aiden Dillard performed in an art noise band, called Ballscarf, that incorporated video projections and Aiden Dillard's own nudity to produce an effect that was described as "nightmaris chaos".  In 2013, Aiden Dillard moved back to North Carolina and began to focus on visual art.  In 2014 Troma Entertainment released Aiden Dillard's campy yet bloody slasher film "Bikini Swamp Girl Massacre" on DVD.

Michael Herz (producer): Michael Herz is an American film producer, director and screenwriter.  With Lloyd Kaufman, the two are the co-founders of Troma Entertainment, the world's longest running independent film studio, known for their comedic horror films, including the cult favorite "Toxic Avenger series and "Tromeo and Juliet".

Supporting paragraphs: Lloyd Kaufman Joseph Ruben
Answer: Joseph Porter Ruben