Orpheus with his lute made trees,
And the mountain tops that freeze,
Bow themselves when he did sing:
To his music plants and flowers
Ever sprung; as sun and showers
There had made a lasting spring.
Every thing that heard him play,
Even the billows of the sea,
Hung their heads, and then lay by.
In sweet music is such art,
Killing care and grief of heart
Fall asleep, or hearing, die.
The woods decay, the woods decay and fall,
The vapours weep their burthen to the ground,
Man comes and tills the field and lies beneath,
And after many a summer dies the swan.
Me only cruel immortality
Consumes: I wither slowly in thine arms,
Here at the quiet limit of the world,
A white-hair’d shadow roaming like a dream
The ever-silent spaces of the East,
Far-folded mists, and gleaming halls of morn …
I would have to say B. But don't rely on this! Here is my explanation;
High-born would mean that he is more important or in a higher grade. In this text, he refers him to be high-born because he is rich and she loves him. He [not the high-born] Loves her so much, he is there when she is on the boat [or what he refers to], her death, and more places [I have not read this poem in a while].
Then again, don't rely on this answer! I did my best. It was either B. or C. to me. B. made more sense to me, but we are two different people!
Carl Sandberg is describing the pleasant feeling of being shrouded in fog and how it arrives gently, sits for awhile then moves on so is unobtrusive whereas Robert Frost in Mending Wall there is a strong skepticism about his neighbour's dictum that "good walls make good neighbours" and his feelings of misgivings about maintaining a wall between adjacent properties when there are no cows to corral or no obvious practical reasons for the wall.