Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth;
This is where we start to think about the metaphorical meanings of this poem. If our speaker is, as we suspect, at a fork in the road of his life, and not at an actual road, he could be trying to peer into his future as far as he can. But, since he can't really predict the future, he can only see part of the path. Who knows what surprises it could hold.
Thus,
The best answer would be;
C. To trace its sinuous, snake-like form.