Read the excerpt from John F. Kennedy's inaugural address:

"Now the trumpet summons us again—not as a call to bear arms, though arms we need—not as a call to battle, though embattled we are—but a call to bear the burden of a long twilight struggle, year in and year out, rejoicing in hope, patient in tribulation—a struggle against the common enemies of man: tyranny, poverty, disease, and war itself. Can we forge against these enemies a grand and global alliance, North and South, East and West, that can assure a more fruitful life for all mankind? Will you join in that historic effort? In the long history of the world, only a few generations have been granted the role of defending freedom in its hour of maximum danger. I do not shrink from this responsibility—I welcome it."

Which statement best explains Kennedy's message in this excerpt?

A. American citizens must be prepared for war.
B. The United States is prepared to protect freedom.
C. The United States is the greatest country in the world.
D. American citizens have a history of protecting democracy.