Question: HMS "Duncan" is the sixth and last of the Type 45 destroyer, an advanced class of six guided missile destroyers built for whose Royal Navy?
Context: The 18 "Forrest Sherman"-class destroyers were the first US post-war destroyers (DD-927 to DD-930 were completed as destroyer leader configurations).  Commissioned beginning in 1955, these ships served until the late 1980s.  Their weaponry underwent considerable modification during their years of service.  Four were converted to guided missile destroyers.  This class also served as the basis for the "Charles F. Adams"-class guided missile destroyer. The Farragut"-class destroyer was a group of 10 guided missile destroyers built for the United States Navy (USN) during the 1950s.  They were the second destroyer class to be named for Admiral David Farragut.  The class is sometimes referred to as the Coontz" class, since "Coontz" was first to be designed and built as a guided missile ship, whereas the previous three ships were designed as all-gun units and converted later. USS "Cole" (DDG-67) is an "Arleigh Burke"-class Aegis-equipped guided missile destroyer homeported in Naval Station Norfolk, Virginia.  "Cole" is named in honor of Marine Sergeant Darrell S. Cole, a machine-gunner killed in action on Iwo Jima on 19 February 1945, during World War II.  "Cole" is one of 62 authorized "Arleigh Burke"-class guided missile destroyers, and one of 21 members of the Flight I-class that utilized the 5 in /54 caliber gun mounts found on the earliest of the "Arleigh Burke"-class destroyers.  The ship was built by Ingalls Shipbuilding and was delivered to the Navy on 11 March 1996. The Kashin-class destroyers were a group of guided missile destroyers built for the Soviet Navy in the 1960s and early 1970s.  Their Soviet designation was Project 61.  s of 2016 , one ship is in service with the Russian Navy, and five modified ships are in service with the Indian Navy as "Rajput"-class destroyer s. The Type 23 frigate or "Duke"-class is a class of frigate built for the United Kingdom's Royal Navy.  The ships are named after British Dukes, thus leading to the class being commonly known as the "Duke"-class.  The first Type 23 was commissioned in 1989, and the sixteenth, HMS "St Albans" was commissioned in June 2002.  They form the core of the Royal Navy's destroyer and frigate fleet and serve alongside the Type 45 destroyers. Originally designed for anti-submarine warfare in the North Atlantic, the Royal Navy’s Type 23 frigates have proven their versatility in warfighting, peace-keeping and maritime security operations around the globe.  Thirteen Type 23 frigates remain in service with the Royal Navy, with three vessels having been sold to Chile and handed over to the Chilean Navy. HMS "Daring" is the lead ship of the Type 45 or "Daring"-class air-defence destroyers built for the Royal Navy, and the seventh ship to hold that name.  She was launched in 2006 on the Clyde and conducted contractor's sea trials during 2007 and 2008.  She was handed over to the Royal Navy in December 2008, entered her base port of Portsmouth for the first time in January 2009 and was formally commissioned on 23 July 2009.  As the lead ship of the first destroyer class built for the Royal Navy since the Type 42 in the 1970s, she has attracted significant media and public attention.  Her name, crest and motto are a reference to the Roman youth Gaius Mucius Scaevola, famed for his bravery. The Royal Navy is the principal naval warfare service branch of the British Armed Forces.  As of January 2017, there are 77 commissioned ships in the Royal Navy.  19 of the commissioned vessels are major surface combatants (six guided missile destroyers and 13 frigates) and 10 are nuclear-powered submarines (four ballistic missile submarines and six fleet submarines).  In addition the Navy possesses a landing platform helicopter, two amphibious transport docks, 15 mine countermeasures vessels, 22 patrol vessels, four survey vessels, one icebreaker and two historic warships ("Victory" and "Bristol"). The "Charles F. Adams" class is a ship class of 29 guided missile destroyers built between 1958 and 1967.  Twenty three destroyers were built for the United States Navy, three for the Royal Australian Navy, and three for the West German "Bundesmarine".  The design of these ships was based on that of "Forrest Sherman"-class destroyer s, but the "Charles F. Adams" class were the first class designed to serve as guided missile destroyers.  19 ft of length was added to the center of the design of the "Forrest Sherman" class to carry the ASROC launcher.  The "Charles F. Adams"-class destroyers were the last steam turbine-powered destroyers built for the U.S. Navy.  Starting with the later "Spruance"-class destroyer s, all U.S. Navy destroyers have been powered by gas turbines.  Some of the destroyers of the "Charles F. Adams" class served during the blockade of Cuba in 1962 and during the Vietnam War. The Type 45 destroyer, also known as the D or "Daring" class, is an advanced class of six guided missile destroyers built for the United Kingdom's Royal Navy.  The class is primarily designed for anti-aircraft and anti-missile warfare and is built around the PAAMS (Sea Viper) air-defence system utilizing the SAMPSON AESA and the S1850M long-range radars.  The first three destroyers were assembled by BAE Systems Surface Fleet Solutions from partially prefabricated "blocks" built at different shipyards, the remaining three were built by BAE Systems Maritime – Naval Ships.  The first ship in the "Daring" class, HMS "Daring", was launched on 1 February 2006 and commissioned on 23 July 2009. HMS "Duncan" is the sixth and last of the Type 45 or "Daring"-class air-defence destroyers built for the Royal Navy.  "Duncan" is named after Adam Duncan, Viscount Duncan of Camperdown (1 July 1731 – 4 August 1804), who defeated the Dutch fleet at the Battle of Camperdown on 11 October 1797.
Answer: United Kingdom's