Information: - The Thompson submachine gun is an American submachine gun, invented by John T. Thompson in 1918, that became infamous during the Prohibition era. It was a common sight in the media of the time, being used by both law enforcement officers and criminals. The Thompson submachine gun was also known informally as the "Tommy Gun", "Annihilator", "Chicago Typewriter", "Chicago Piano", "Chicago Style", "Chicago Organ Grinder", "Trench Broom", "Trench Sweeper", "The Chopper", and simply "The Thompson". - The Arsenal M23 submachine gun ( Estonian : Arsenali pustolkuulipilduja ) ( also known as Arsenal Tallinn ) was an Estonian submachine gun from 1926 through 1935 . These submachine guns were designed and produced in the Estonian military equipment factory '' Arsenal '' in Karjamaa , Tallinn , but production was not more than 600 units . The weapon was chambered for the 9x20 mm semi-rimmed Browning cartridge to be compatible with ammunition for the Browning FN M1903 pistol which had been adopted by the Estonian Army . It operated on the blowback system and was essentially similar to the MP18.1 ; having a wooden stock , slotted barrel jacket , and horizontal left side magazine feed . A uniquely slender 40 round single column box magazine led to frequent cartridge feeding problems ; and cooling fins which were machined lengthwise along the barrel to promote cooling air flow when firing ( similar to the Lewis machine gun ) , unnecessarily complicated production . It was used by the combat support units of the Border Guard , the Estonian Defence League and the Estonian Defence Forces . The Arsenal submachine gun was replaced in Estonian service by the Finnish Suomi KP / -31 submachinegun in 1938 . The Estonian Army sold a few samples to Latvia and all of the remainder found their way to Republican forces during the Civil War in Spain . - A submachine gun (SMG) is an air-cooled, magazine-fed, automatic carbine designed to fire pistol cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun. - John Taliaferro (pronounced "tolliver") Thompson, (December 31, 1860 June 21, 1940), was a United States Army officer best remembered as the inventor of the Thompson submachine gun. - Tallinn (or ) is the capital and largest city of Estonia. It is situated on the northern coast of the country, on the shore of the Gulf of Finland, south of Helsinki, east of Stockholm and west of Saint Petersburg. From the 13th century until 1918 (and briefly during the Nazi occupation of Estonia from 1941 to 1944), the city was known as Reval. Tallinn occupies an area of and has a population of 443,894. Approximately 32% of Estonia's total population lives in Tallinn. - Saint Petersburg is Russia's second-largest city after Moscow, with fivemillion inhabitants in 2012, and an important Russian port on the Baltic Sea. It is politically incorporated as a federal subject (a federal city). Situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea, it was founded by Tsar Peter the Great on May . In 1914, the name was changed from Saint Petersburg to Petrograd, in 1924 to Leningrad, and in 1991 back to Saint Petersburg. Between 17131728 and 17321918, Saint Petersburg was the imperial capital of Russia. In 1918, the central government bodies moved to Moscow. What object entity has the relation of 'service retirement' with the subject 'arsenal submachine gun'? Choices: - 1860 - 1918 - 1940 - 1941 - 1944 - 2012
The answer to this question is:
1940