On thy cold gray stones, O Sea!
And I would that my tongue could utter
The thoughts that arise in me.
O well for the fisherman's boy,
That he shouts with his sister at play!
O well for the sailor lad,
That he sings in his boat on the bay!

Which of these poetic techniques is illustrated in these lines?

A. symbolism
B. allusion
C. juxtaposition
D. paradox