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In this task, you are given a context, a subject, a relation, and many options. Based on the context, from the options select the object entity that has the given relation with the subject. Answer with text (not indexes).

Context: The American Locomotive Company, often shortened to ALCO, ALCo or Alco, designed, built and sold steam locomotives, diesel-electric locomotives, diesel engines and generators, specialized forgings, high quality steel, armed tanks and automobiles and produced nuclear energy. The American Locomotive Company was formed in 1901 by the merger of Schenectady Locomotive Engine Manufactory of Schenectady, New York with seven smaller locomotive manufacturers., The ALCO RSD - 7 was a diesel - electric locomotive of the road switcher type built by ALCO at Schenectady , New York between January 1954 and April 1956 . Two versions were built , with the same RSD - 7 model designation but different specifications and power ratings , although both used the ALCO 244 engine in V16 configuration . Specification DL - 600 , of which only two were built , developed 2,250 hp ( 1,678 kW ; 2,281 PS ) and used the 244G engine . The revised specification DL - 600A , numbering 27 locomotives , was rated at 2,400 hp ( 1,790 kW ; 2,433 PS ) and used the 244H engine . The RSD - 7 was superseded by the ALCO 251 - engined ALCO RSD - 15 , which looks very similar . The RSD - 7 was the last ALCO diesel built with a 244 engine . Both rode on a pair of three - axle trucks with all three axles on each truck powered ; this is a C - C wheel arrangement . These trucks have an unequal axle spacing due to traction motor positioning ; the outer two axles on each truck are closer together than the inner two . The RSD - 7 used the GE 752 traction motor . The six - motor design allowed better tractive effort at lower speeds ., A locomotive or engine is a rail transport vehicle that provides the motive power for a train. The word originates from the Latin "loco" "from a place", ablative of "locus", "place" + Medieval Latin "motivus", "causing motion", and is a shortened form of the term "locomotive engine", first used in the early 19th century to distinguish between mobile and stationary steam engines., A road switcher is a type of railroad locomotive which was originally employed for delivering or picking up railcars outside of a railroad yard. Both type and term are North American in origin, although similar types have been used elsewhere. Since the road switcher must work some distance away from a yard, it must be able to operate at road speeds, it must also have high-visibility while it is switching, and it must have the ability to run in both directions. Additionally, a road switcher must have the power rating and cooling capacity of a traditional road engine, and a road switcher must have high-speed (i.e., road) trucks, not low-speed (i.e., switcher) trucks. Modern road trucks are always equipped with (frictionless) roller bearings; switcher trucks were almost always equipped with (friction) plain bearings, until such bearings were outlawed in interchange service on railcars "and" locomotives., The ALCO RSD-15 was a diesel-electric locomotive of the road switcher type built by ALCO (the American Locomotive Company) of Schenectady, New York between August 1956 and June 1960, during which time 75 locomotives were produced. The RSD-15 was powered by an ALCO 251 16-cylinder four-cycle V-type prime mover rated at ; it superseded the almost identical ALCO 244-engined RSD-7, and was catalogued alongside the similar but smaller RSD-12, powered by a 12-cylinder 251-model V-type diesel engine., The Alco 251 is a 4-stroke diesel engine that was developed by the American Locomotive Company to replace the 244 and 539 engines. The 251 was developed to be used in diesel locomotives, as a marine power plant in ships and as a stationary power generator. , A switcher or shunter (Great Britain: "shunter"; Australia: "shunter" or yard pilot; United States: "switcher", switch engine, or yard goat, except Pennsylvania Railroad: shifter) is a small railroad locomotive intended not for moving trains over long distances but rather for assembling trains ready for a road locomotive to take over, disassembling a train that has been brought in, and generally moving railroad cars around a process usually known as "switching" (USA) or "shunting" (UK). They do this in classification yards (Great Britain: "marshalling yards"). Switchers may also make short transfer runs and even be the only motive power on branch lines and switching and terminal railroads. The term can also be used to describe the workers operating these engines or engaged in directing shunting operations., Schenectady is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2010 census, the city had a population of 66,135. The name "Schenectady" is derived from a Mohawk word "skahnehtati" meaning "beyond the pines". The city was founded on the south side of the Mohawk River by Dutch colonists in the 17th century, many from the Albany area. They were prohibited from the fur trade by the Albany monopoly, which kept its control after the English takeover in 1664. Residents of the new village developed farms on strip plots along the river., Subject: alco rsd-7, Relation: manufacturer, Options: (A) american locomotive company (B) pennsylvania railroad (C) seat (D) train
Output:
american locomotive company