We know that Britain and Americans didn't really have the best of relationships so B, C, and D aren't believable because they are hinting that Americans had a great respect for Britain. Americans felt as if the Proclamation of 1763 was ignoring their rights so they decided to ignore it and head west anyway.
The Nile river was used as a major trade route. Also, they built deep holesin the ground for when the Nile floods every year. this way they had water to last.
