Why does mathew arnold mention sophocles in this excerpt from “dover beach”?

with tremulous cadence slow, and bring
the eternal note of sadness in.

sophocles long ago
heard it on the aegean, and it brought
into his mind the turbid ebb and flow
of human misery; we
find also in the sound a thought,
hearing it by this distant northern sea.

it enhances the dramatic quality of the poem.
sophocles drew inspiration from the sea.

it enhances the melancholic tone of the poem.
sophocles inspires the poet to write.