Question: Which producer both created the character of Dr. Izzie Stevens and also wrote the Dr. Izzie-focused episode "Time Has Come Today"
Context: "Wishin' and Hopin'" is the fourteenth episode of the third season of the American television medical drama "Grey's Anatomy", and the show's 50th episode overall.  It was written by Tony Phelan and Joan Rater and directed by Julie Anne Robinson.  The episode originally aired on the American Broadcasting Company (ABC) in the United States on February 1, 2007.  In the episode, Dr. Meredith Grey (Ellen Pompeo) struggles with her Alzheimer's-stricken mother, Ellis Grey (Kate Burton), becoming temporarily lucid.  Further storylines include Dr. Izzie Stevens (Katherine Heigl) and Dr. Miranda Bailey (Chandra Wilson) continuously seeking patients for their new clinic, Dr. Richard Webber (James Pickens, Jr.) dealing with the repercussions of his upcoming retirement, and Dr. George O'Malley (T.R. Knight) facing negative response from colleagues on his unexpected marriage to Dr. Callie Torres (Sara Ramirez). "Tainted Obligation" is the fourth episode of the sixth season of the American television medical drama "Grey's Anatomy", and the show's 106th episode overall.  It was written by Jenna Bans and directed by Tom Verica.  The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on October 8, 2009.  In the episode, Dr. Meredith Grey (Ellen Pompeo) and Dr. Lexie Grey (Chyler Leigh)'s father is admitted into the hospital, seeking a liver transplantation.  Further storylines include Dr. Cristina Yang (Sandra Oh) getting nervous about losing her job, and Dr. Owen Hunt (Kevin McKidd) attempting to perform surgery on a terminal patient with Dr. Izzie Stevens (Katherine Heigl). "Goodbye" is the second episode of the sixth season of the American television medical drama "Grey's Anatomy", and the show's 104th episode overall.  It was written by Krista Vernoff and directed by Bill D'Elia.  The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on September 24, 2009.  In "Goodbye", the staff at Seattle Grace Hospital come to terms with the death of their colleague Dr. George O'Malley (T.R. Knight).  Further storylines include Dr. Richard Webber (James Pickens, Jr.) being engaged in a vehicular collision, Dr. Callie Torres (Sara Ramirez) receiving a job as an attending physician at a neighboring hospital, and Dr. Alex Karev (Justin Chambers)'s marriage with Dr. Izzie Stevens (Katherine Heigl) taking a toll after her near-death experience. "Time Has Come Today" is the first episode of the third season of the American television medical drama "Grey's Anatomy", and the show's 37th episode overall.  Written by Shonda Rhimes and directed by Daniel Minahan, the episode aired on the American Broadcasting Company (ABC) in the United States on September 21, 2006.  The episode primarily focuses on Dr. Izzie Stevens (Katherine Heigl) coping with the unexpected death of her fiancé, Denny Duquette (Jeffrey Dean Morgan), while dealing with the decision to quit the internship program.  Further storylines include Dr. Preston Burke (Isaiah Washington) facing the repercussions of his being shot, and Dr. Meredith Grey (Ellen Pompeo) dealing with the aftermath of her affair with Dr. Derek Shepherd (Patrick Dempsey), which puts a strain in his already troubled marriage to Dr. Addison Montgomery-Shepherd (Kate Walsh). "Invest in Love" is the eighth episode of the sixth season of the American television medical drama "Grey's Anatomy", and the show's 110th episode overall.  Written by Stacy McKee and directed by Jessica Yu, the episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on November 5, 2009.  "Grey's Anatomy" centers around a group of young doctors, training to be seasoned professionals.  In this episode, Dr. Arizona Robbins (Jessica Capshaw) is stunned when her longtime patient's parents offer the hospital a donation of twenty-five million dollars.  Katherine Heigl (Dr. Izzie Stevens) was absent from the episode, as she was filming the 2010 blockbuster "Life as We Know It".  The original episode broadcast was ranked #3 for the night and would have 13.95 million viewers, garnered a 5.1/13 Nielsen rating/share in the 18–49 demographic. "Good Mourning" is the first episode of the sixth season of the American television medical drama "Grey's Anatomy", and the show's 103rd episode overall.  It was written by Krista Vernoff and directed by Ed Ornelas.  The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on September 24, 2009.  In "Good Mourning", the physicians are seen dealing with the revelation that a dead John Doe is their beloved co-worker Dr. George O'Malley (T.R. Knight), and dealing with the aftermath of Dr. Izzie Stevens (Katherine Heigl)'s near-death experience.  Further storylines include Dr. Callie Torres (Sara Ramirez) and Stevens trying to decide whether or not to donate O'Malley's organs and Dr. Derek Shepherd (Patrick Dempsey) being offered Dr. Richard Webber (James Pickens, Jr.)'s chief of surgery job. "I Always Feel Like Somebody's Watchin' Me" is the third episode of the sixth season of the American television medical drama "Grey's Anatomy", and the show's 105th episode overall.  It was written by Tony Phelan and Joan Rater, and directed by Michael Pressman.  The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on October 1, 2009.  In the episode, the physicians of Seattle Grace struggle to maintain their jobs as the hospital merges with Mercy West.  Further storylines include Dr. Cristina Yang (Sandra Oh) working under Dr. Arizona Robbins (Jessica Capshaw), and Dr. Izzie Stevens (Katherine Heigl) returning to work full-time, too quickly after her surgery. "Losing My Religion" is the twenty-seventh and final episode of the second season of the American television medical drama "Grey's Anatomy", and the show's 36th episode overall.  Written by Shonda Rhimes and directed by Mark Tinker, the episode was originally broadcast with "Deterioration of the Fight or Flight Response", in a two-hour season finale event on the American Broadcasting Company (ABC) in the United States on May 15, 2006.  "Grey's Anatomy" centers around a group of young doctors in training.  In this episode, Dr. Izzie Stevens (Katherine Heigl) and her fellow interns have to plan a prom for Dr. Richard Webber's (James Pickens, Jr.) niece Camille Travis (Tessa Thompson).  Further storylines include Dr. Preston Burke (Isaiah Washington) recovering from his gunshot wound and Denny Duquette's (Jeffrey Dean Morgan) death following his seemingly successful heart transplant surgery. "Invasion" is the fifth episode of the 6th season of the American television medical drama "Grey's Anatomy", and the show's 107th episode overall.  It was written by Mark Wilding and directed by Tony Phelan.  The episode was originally broadcast on the American Broadcasting Company (ABC) in the United States on October 15, 2009.  In the episode, the physicians of Seattle Grace Hospital must learn to co-operate with new Mercy West residents, who do not act in a kind manner to them.  Other storylines include Dr. Callie Torres (Sara Ramirez)'s father returning to the hospital to condemn her homosexuality, and Dr. Izzie Stevens (Katherine Heigl) putting her career into jeopardy after administering the wrong treatment to a patient. Isobel Katherine "Izzie" Stevens, M.D. is a fictional character from the medical drama television series "Grey's Anatomy", which airs on the American Broadcasting Company (ABC) in the United States.  The character was created by series producer Shonda Rhimes, and was portrayed by actress Katherine Heigl from 2005 to 2010.  Introduced as a surgical intern at the fictional Seattle Grace Hospital, Izzie worked her way up to resident level, while her relationships with her colleagues Meredith Grey (Ellen Pompeo), Cristina Yang (Sandra Oh), George O'Malley (T.R. Knight) and Alex Karev (Justin Chambers) formed a focal point of the series.
Answer: Shonda Rhimes