Question: The GBU-28 was originally produced by an arsenal located on the bank of what river?
Context: The Watertown Arsenal was a major American arsenal located on the northern shore of the Charles River in Watertown, Massachusetts.  The site is now registered on the ASCE's List of Historic Civil Engineering Landmarks and on the U.S.'s National Register of Historic Places, and it is home to a park, restaurants, mixed use office space, and currently serves as the national headquarters for athenahealth. Hikari Naval Arsenal (光海軍工廠 , Hikari kaigun kōshō ) was a naval arsenal located in Hikari, Yamaguchi Prefecture, Japan.  It opened on October 1, 1940.  It produced steel, engines, cannon, torpedoes, and bombs for the Imperial Japanese Navy.  It was bombed on the afternoon of August 14, 1945 (the day before the official Surrender of Japan) by four B-29 bomber groups.  The raid was reported to have taken place after Emperor Hirohito had begun his surrender message to the Japanese people.  It was carried out by the XXI Bomber Command, classified as mission 325.  Its target code was "Thunderhead" Arsenal is a London Underground station located in Highbury, London.  It is on the Piccadilly line, between Holloway Road and Finsbury Park stations, in Travelcard Zone 2.  Originally known as Gillespie Road, it was renamed in 1932 after Arsenal Football Club, who at the time played at the nearby Arsenal Stadium.  It is the only tube station named directly after a football club in the United Kingdom.  Although Arsenal's Highbury Stadium closed in 2006, the station retains its name and is still used by spectators attending matches at Arsenal's new Emirates Stadium, but it is otherwise quieter than other stations on the same stretch of line. London City Airport is a station on the Docklands Light Railway (DLR) serving London City Airport in east London, which is on the Woolwich Arsenal branch.  It opened on 2 December 2005.  It was first located on what was initially King George V branch, and was, until the extension to Woolwich Arsenal was completed, the reason for this branch.  It continues to be an important station on the DLR.  Trains run westbound to Bank in the City of London, northbound to Stratford International and eastbound to Woolwich Arsenal.  The station is in the London Borough of Newham and is located in Travelcard Zone 3. The Pontiac Storage Facility is a former storage facility of the United States Army that stored equipment for the Detroit Arsenal located in Pontiac, Michigan.  It was closed as part of the 1988 Base Realignment and Closure Commission. Joliet Army Ammunition Plant (JOAAP, formerly known as the Joliet Arsenal) was a United States Army arsenal located in Will County, Illinois, near Elwood, Illinois, south of Joliet, Illinois.  Opened in 1940 during World War II, the facility consisted of the Elwood Ordnance Plant (EOP) and the Kankakee Ordnance Works (KNK).  In 1945, the two were deactivated and combined forming the Joliet Arsenal.  The plant was reactivated for the Korean War and renamed Joliet Army Ammunition Plant during the Vietnam War.  Production of TNT ended in 1976, and the major plant operations closed shortly after in the late 1970s.  The facility briefly revived an automated load-assemble-pack (LAP) artillery shell operation that was managed by the Honeywell Corporation during the Reagan administration in the 1980s before it was finally closed. The GBU-28 is a 5,000-pound (2,268 kg) laser-guided "bunker busting" bomb produced originally by the Watervliet Arsenal, Watervliet, New York.  It was designed, manufactured, and deployed in less than three weeks due to an urgent need during Operation Desert Storm to penetrate hardened Iraqi command centers located deep underground.  Only two of the weapons were dropped in Desert Storm, both by F-111Fs.  One GBU-28 was dropped during Operation Iraqi Freedom. The Watervliet Arsenal is an arsenal of the United States Army located in Watervliet, New York, on the west bank of the Hudson River.  It is the oldest continuously active arsenal in the United States, and today produces much of the artillery for the army, as well as gun tubes for cannons, mortars, and tanks.  It has been a National Historic Landmark since 1966. The Rock Island Arsenal comprises 946 acres , located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois.  It lies within the state of Illinois.  It is home of First Army headquarters.  The island was originally established as a government site in 1816, with the building of Fort Armstrong.  It is now the largest government-owned weapons manufacturing arsenal in the United States.  It has manufactured military equipment and ordnance since the 1880s.  In 1919–1920 one hundred of the Anglo-American or Liberty Mark VIII tanks were manufactured, although too late for World War I.  It is designated as a National Historic Landmark. Nappo is a diamond-shaped German candy, chocolate-covered nougat, that has been produced since 1925.  Nappo was originally produced in Krefeld by Dr. Helle & Co.  GmbH, founded in 1920, which originally produced peppermints.
Answer: Hudson River