Read the poem.
The Wild Swans at Coole
by William Butler Yeats
The trees are in their autumn beauty,
The woodland paths are dry,
Under the October twilight the water
Mirrors a still sky; Upon the brimming water among the stones
Are nine and fifty swans.
The nineteenth Autumn has come upon me
Since I first made my count;
I saw, before I had well finished,
All suddenly mount
And scatter wheeling in great broken rings
Upon their clamorous wings
I have looked upon those brilliant creatures,
And now my heart is sore
All's changed since I, hearing at twilight,
The first time on this shore,
The bell-beat of their wings above my head,
Trod with a lighter tread.
Unwearied still, lover by lover,
They paddle in the cold,
Companionable streams or climb the air;
Their hearts have not grown old;
Passion or conquest, wander where they will, Attend upon them still.
But now they drift on the still water
Mysterious, beautiful;
Among what rushes will they build,
By what lake's edge or pool
Delight men's eyes, when I awake some day
To find they have flown away?
How does the personification in the line "Their hearts have not grown old" in Stanza 4 affect the poem?
A. It shows that the swans have the companionship of each other.
B. It shows that the swans are aimless creatures.
C. It shows that the swans remain youthful year after year.
D. It shows that the swans' lives are filled with wanderlust.