Question: The Millionaires' Unit is a documentary that was narrated by which actor?

Context paragraphs:
Sudden Impact (TV series): Sudden Impact is an Australian observational documentary series that airs on the Nine Network.  It debuted on 9 December 2008 at 8pm.  The program was developed in association with the Transport Accident Commission (TAC), and is narrated by Gary Sweet.  The program is largely set in Victoria.  The series is similar to the New Zealand based show "Serious Crash Unit" and Seven Network’s "Crash Investigation Unit".

Medical Emergency (TV series): Medical Emergency is an Australian reality television series screened on the Seven Network.  "Medical Emergency" is narrated by actor Chris Gabardi who also appeared in drama series "All Saints".  It was previously hosted and narrated by actress Georgie Parker, who also appeared in "All Saints".  "Medical Emergency" is filmed under strict protocol at Melbourne's Alfred Hospital's trauma unit.

Bruce Dern: Bruce MacLeish Dern (born June 4, 1936) is an American actor, often playing supporting villainous characters of unstable nature.  He was nominated for the Academy Award for Best Supporting Actor for "Coming Home" (1978) and the Academy Award for Best Actor for "Nebraska" (2013).  His other film appearances include "The Cowboys" (1972), "Black Sunday" (1977), "Monster" (2003), and "The Hateful Eight" (2015).

The Millionaires' Unit: The Millionaires' Unit is a 2015 American documentary film by Darroch Greer and Ron King about the First Yale Unit, a group of Yale college students who took the initiative to learn to fly in preparation for America's entry into the Great War.  Based on a book by author Marc Wortman, the film is narrated by Academy Award-nominated actor Bruce Dern.  It was filmed in the U.S., England, France, Belgium and New Zealand over the course of seven years.  The documentary charts the romantic, little-known story of the origins of American airpower and features sequences filmed air-to-air with original WW1 planes.

Millionaires Mansions: Millionaires Mansions was a TV documentary produced by BAFTA-winning Indus Films and shown on British television Channel 4 in 2016.

BBC Wildlife Specials: The BBC Wildlife Specials are a series of nature documentary programmes commissioned by BBC Television.  The series premiered in 1995, and 22 specials have been produced to date, with most of the more recent ones consisting of multiple episodes.  The earlier programmes were produced in-house by the BBC's Natural History Unit, but the more recent "Spy in the ..." titles were made by the independent John Downer Productions.  The first 18 specials, through 2008, were narrated by David Attenborough.  "Polar Bear: Spy on the Ice" (2010), "Penguins: Spy in the Huddle" (2013) and "Dolphins: Spy in the Pod" (2014) were narrated by David Tennant.

Night Mail: Night Mail is a 1936 documentary film about a London, Midland and Scottish Railway (LMS) mail train from London to Scotland, produced by the GPO Film Unit.  The film ends with a "verse commentary" by W. H. Auden, written for existing footage.  Benjamin Britten scored the film.  The film was directed by Harry Watt and Basil Wright, and narrated by John Grierson and Stuart Legg.  The Brazilian filmmaker Alberto Cavalcanti was sound director.  The locomotive featured in the film was Royal Scot 6115 "Scots Guardsman", built in 1927.  The film has become a classic of its own kind, much imitated by adverts and modern film shorts.  "Night Mail" is widely considered a masterpiece of the British Documentary Film Movement.

List of Meerkat Manor episodes: The episodes of the British documentary "Meerkat Manor" first premiered on Animal Planet International in the United Kingdom on 12 September 2005.  The programme was originally created by Caroline Hawkins, executive producer and series editor at Oxford Scientific Films, and commissioned for Animal Planet International by executive producer and commissioning editor Mark Wild.  The original episodes are narrated by Bill Nighy.  The Australian and American channels redubbed the episodes using their own narrators.  the Australian episodes are narrated by Mike Goldman.  In the US, episodes for the first three series were narrated by Sean Astin.  For the fourth series, Astin was replaced with Stockard Channing.  "Meerkat Manor" is also broadcast in more than 160 countries.

The Secret Millionaire: The Secret Millionaire is a reality television show which originated in the UK, in which millionaires go incognito into impoverished communities and agree to give away tens of thousands of pounds (or tens of thousands of dollars in the US and Australian versions).  Members of the community are told the cameras are present to film a documentary.  The UK version is produced by production company RDF Media.  It first aired in 2006 on Channel 4, with further series in subsequent years.

Police Interceptors: Police Interceptors is a British TV documentary series that profiles the work of: a police ANPR Intercept Team (now known as the Territorial Support Team) in Essex (series 1, 2 and 3); South Yorkshire Police's Road Crime Unit and Derbyshire Police's Road Policing Unit (series 4); The Cumbria Constabulary's Roads Policing Unit (series 5); Lincolnshire's specialist police Road Policing Unit (series 6, 7 and 8); The Durham Constabulary and Cleveland Police's Special Operations Unit (series 9 to 11); and Cheshire Constabulary (series 12).  The Durham Constabulary and Cleveland Police's Special Operations Unit returned as the hosts in September 2017 (series 13).  The documentary has been broadcast by Channel 5 since the first episode on 9 May 2008.  The show is produced by the same people who did former Sky series "Road Wars".

Supporting paragraphs: The Millionaires' Unit Bruce Dern
Answer: Bruce MacLeish Dern