Question: Who plays the primary antagonist in Kenneth Branagh's adaptation of Hamlet?
Context: Rufus Frederik Sewell ( ; born 29 October 1967) is an English actor.  In film, he has appeared in Kenneth Branagh's rendition of "Hamlet" (1996) playing Fortinbras, "The Woodlanders", "Dangerous Beauty", "Dark City", "A Knight's Tale", "The Illusionist", "Tristan and Isolde", and "Martha, Meet Frank, Daniel and Laurence".  On television, he starred as "Obergruppenführer" John Smith in "The Man in the High Castle", an Italian detective in the BBC's television series "Zen" (2011) and also appeared in the mini-series "The Pillars of the Earth" (2010).  In 1993 he played the hero, Will Ladislaw, in the BBC's adaptation of George Eliot's "Middlemarch".  In 2003, he appeared in the lead role in "".  He starred in the CBS drama "Eleventh Hour", which was cancelled in April 2009.  On stage, he originated the role of Septimus Hodge in Tom Stoppard's "Arcadia" and the role of Jan in Stoppard's "Rock 'n' Roll"; the latter earned him an Olivier Award and a Tony Award nomination. Richard Crosby Pearce (born 1961 in St Albans, England) is a British actor, primarily in voice acting.  Pearce has appeared in over 500 radio dramas and was twice a member of the BBC Radio drama company.  He played opposite Sir John Gielgud in "Tales My Father Taught Me" and in a variety of radio parts ranging from The Mekon in "Dan Dare" to the last castrato in "Angel of Rome".  In 1992 and 1993, Pearce appeared in the BBC Radio adaptation of "The Adventures of Tintin", playing the eponymous hero.  His other audio work includes Kenneth Branagh's "Romeo and Juliet" (Renaissance), "The Taming of the Shrew" (BBC), "Hamlet" (Naxos), "The Skull Beneath The Skin" by PD James (BBC), "Oliver Twist" (BBC), "A Woman of No Importance" (Penguin), and two of BBC audio's highest selling audio series: "The Adventures of Tintin" (BBC) and "Doctor Who", playing Jeremy Fitzoliver, one of the doctor's companions in two specially commissioned episodes "The Paradise of Death" and "The Ghosts of N-Space". Love's Labour's Lost is a 2000 adaptation of the comic play of the same name by William Shakespeare, directed by and starring Kenneth Branagh.  It was the first feature film to be made of this lesser-known comedy.  Branagh's fourth film of a Shakespeare play (he did not direct the 1995 "Othello", although he did play Iago), "Love's Labour's Lost" was a box-office and critical disappointment. Hamlet is a 1996 film adaptation of William Shakespeare's play "Hamlet", adapted for the screen and directed by Kenneth Branagh, who also stars in the titular role as Prince Hamlet.  The film also features Derek Jacobi as King Claudius, Julie Christie as Queen Gertrude, Kate Winslet as Ophelia, Michael Maloney as Laertes, Richard Briers as Polonius, and Nicholas Farrell as Horatio.  Other notable appearances include Robin Williams, Gérard Depardieu, Jack Lemmon, Billy Crystal, Rufus Sewell, Charlton Heston, Richard Attenborough, Judi Dench, John Gielgud and Ken Dodd. My Week with Marilyn is a 2011 British drama film directed by Simon Curtis and written by Adrian Hodges.  It stars Michelle Williams, Kenneth Branagh, Eddie Redmayne, Dominic Cooper, Julia Ormond, Emma Watson and Judi Dench.  Based on two books by Colin Clark, it depicts the making of the 1957 film "The Prince and the Showgirl", which starred Marilyn Monroe (Williams) and Laurence Olivier (Branagh).  The film focuses on the week during the shooting of the 1957 film when Monroe was escorted around London by Colin (Redmayne), after her husband Arthur Miller (Dougray Scott) had returned to the United States. Fortunes of War is a 1987 BBC television adaptation of Olivia Manning's cycle of novels "Fortunes of War".  It stars Kenneth Branagh as Guy Pringle, lecturer in English Literature in Bucharest during the early part of the Second World War, and Emma Thompson as his wife Harriet.  Kenneth Branagh and Emma Thompson met filming the TV series and married in real life.  Other cast members included Ronald Pickup, Robert Stephens, Alan Bennett, Philip Madoc and Rupert Graves.  The series stays relatively faithful to the original novels, with no notable departures from their plot. Over fifty films of William Shakespeare's "Hamlet" have been made since 1900.  Seven post-war "Hamlet" films have had a theatrical release: Laurence Olivier's "Hamlet" of 1948; Grigori Kozintsev's 1964 Russian adaptation; a film of the John Gielgud-directed 1964 Broadway production, "Richard Burton's Hamlet", which played limited engagements that same year; Tony Richardson's 1969 version (the first in colour) featuring Nicol Williamson as Hamlet and Anthony Hopkins as Claudius; Franco Zeffirelli's 1990 version starring Mel Gibson; Kenneth Branagh's full-text 1996 version; and Michael Almereyda's 2000 modernisation, starring Ethan Hawke. King Claudius is a fictional character and the primary antagonist of William Shakespeare's tragedy "Hamlet".  He is the brother to King Hamlet, second husband to Gertrude and uncle and later stepfather to Hamlet.  He obtained the throne of Denmark by murdering his own brother with poison and then marrying the late king's widow.  He is loosely based on the Jutish chieftain Feng who appears in "Chronicon Lethrense" and in Saxo Grammaticus' "Gesta Danorum".  There had never been an actual Danish King of that name. Mary Shelley's Frankenstein is a 1994 horror drama film directed by Kenneth Branagh and starring Robert De Niro, Kenneth Branagh, Tom Hulce, Helena Bonham Carter, Ian Holm, John Cleese, and Aidan Quinn.  The picture was produced on a budget of $45 million and is considered the most faithful film adaptation of Mary Shelley's novel "Frankenstein; or, The Modern Prometheus", despite several differences and additions in plot from the novel. Jack Ryan: Shadow Recruit is a 2014 American action spy thriller film directed by Kenneth Branagh.  Chris Pine, Kevin Costner, Kenneth Branagh, and Keira Knightley star in leading roles.  The film features the fictional character Jack Ryan created by author Tom Clancy.  It is the fifth film in the "Jack Ryan" series but is presented as a reboot that departs from the previous installments.  Unlike its predecessors, it is not an adaptation of a particular Clancy novel, but rather an original story.  Pine stars in the title role, becoming the fourth actor to play Ryan, following Alec Baldwin, Harrison Ford, and Ben Affleck.
Answer: Derek Jacobi