【单选题】

Alaska, which was called RussianAmerica before it was sold to the United States ofAmerica, joined the union as the forty-ninth state in 1959.

Alaska is now the largest of all the 50 states of the United States.
It was in 1867 that President
A、Johnson’s Secretary of State (国务卿) ,Seward boughtAlaska from the Russians at a cost of 7.2 million. The buying of the huge northern land mass seemed at first something foolishly done. Not only wasAlaska difficult to reach, but it was also hard to live in, and it appeared to have no importance in time of war.Besides, there are volcanoes there asAlaska lies on the Pacific "ring of fire" (火山带). InAlaska large treeless areas are covered with snow all the year. For these reasons the buying ofAlaska was called "Seward’s Fooly" at that time.
However, in 1896 gold was found inAlaska, and people poured into the land quickly. Since then other important natural resources were discovered, including oil. Soon people changed their thinking about "Seward’s Fooly" .But most people visitAlaska in order to see the endless beauty of nature that the northern land discloses to them. For instance, there are about 11,000 islands inAlask
A、And in a certain area ofAlaska the sun does not set for 82 days every year.
Tourists came toAlaska to ______.
A、study its importance in war
B．study its volcanoes
C．enjoy its freezing weather
D．enjoy its beauty of nature