The correct answer is option 3: Russia. The USA purchased Alaska from Russia in 1867, in a deal known as the Alaska Purchase. The purchase was negotiated by US Secretary of State William H. Seward and was finalized for a purchase price of $7.2 million. At the time, Alaska was seen as a barren and remote territory, and the purchase was met with skepticism and criticism. However, the discovery of gold and other natural resources in Alaska in the late 19th century changed its perception and value. Alaska became the 49th state of the USA in 1959. It is interesting to note that option 1 (Canada) was not the correct answer, as Alaska shares a border with Canada, but it was not purchased from Canada.