The correct answer is: a labor camp. Actually, Gulag was the agency, made by government, that administered the main Soviet forced labor camp system during the Stalin era, from the 1930s till the 1950s, and this term was also used to describe every labor camp of this kind in USSR. The first ones were created in 1918. The Gulag was the main instrument of political repression in USSR, and many of the people who were sent to these camps were political prisoners, although there were all kinds of criminals... The Gulag was the acronym for the "Main Camp Administration", in Russian.
