Answer:
C) rough, unfinished
Explanation:
This is the excerpt, the first stanza, from the Ralph Waldo Emerson's poem "Concord Hymn" that deals with the beginning of the Independence War against the British.
Now, the word "rude" of course, means impolite, but it can't be used in this context to describe a bridge.
If a bridge looked rude, that was probably due to some defying, scary or maybe even repulsive feeling it provoked.
The reason for a bridge to awake such feelings could be that the bridge is still rough and unfinished or damaged and maybe even partially destroyed.