You can eliminate C, as he says it doesn't matter which road he walks.
You can also eliminate B, as there's no mention of water
That leaves you with A and D, but it couldn't be A as there's no one else there for him to be thinking of. He state's "he was alone in this world of A.D. 2053..." and that also foreshadows time travel or maybe a second dimension. Sounds like a fun story though.
