Which line in this excerpt from Walt Whitman's "O Captain! My Captain!" reflects the theme of patriotism that dominates the poem?
O Captain! my Captain! rise up and hear the bells;
Rise up—for you the flag is flung—for you the bugle trills,
For you bouquets and ribbon’d wreaths—for you the shores a-crowding,
For you they call, the swaying mass, their eager faces turning;
Here Captain! dear father!
This arm beneath your head!
It is some dream that on the deck,
You’ve fallen cold and dead.