Why does Emily Dickinson capitalize most of the nouns in these lines from her poem "A curious Cloud surprised the Sky"?

A curious Cloud surprised the Sky,
'Twas like a sheet with Horns;
The sheet was Blue—
The Antlers Gray—
It almost touched the lawns.

A.
to draw attention to certain ideas
B.
to give the poem a singsong effect
C.
to provide a unique twist to the poem
D.
to reflect the unpredictable nature of life
E.
to divide the important from the mundane