John F. Kennedy was the youngest American to be elected president of the United States. During the World War Ⅱ John F. Kennedy had an outstanding record in the Navy. After the war Kennedy worked briefly as a newspaperman, then entered polities. He was three times elected to the House of Representatives before becoming a senator from Massachusetts. In 1960 he was elected president in a very close race in which there were charges of irregularities.Kennedy’ s term of office was marked by the achievements in appeals to idealism, a broad participation of people in politics, and improved civil rights. In international affairs, Kennedy saw the failure of the American - backed invasion of Cuban missile crisis which brought Russia and the United States to the brink of war.The Kennedy family has experienced victories and tragedy. One of John Kennedy’ s sisters was mentally backward and an old brother was killed in the war. John Kennedy was assassinated -- as was his brother, Robert Kennedy. The family has suffered scandals of sex, alcohol, and drugs in both John’ s generation and in this present generation. Many believe that for the young, wealth and a prominent family too much, too soon, too easy are more of a curse than a help. We learn from the second paragraph that（）

A. when Kennedy was the president, he made some outstanding achievements
B. Kennedy failed his duty as the president of the United States
C. with Kennedy as the president, fewer people concerned themselves with state affairs
D. in Kennedy' s time, the United States, Russia and Cuba all had some problems