The reason the american dream is not worth chasing after, is because it causes greed, anguish, and everything you own. "The american dream" is more like "The american nightmare" if you ask me. People who live the "american dream" Either end up somehow rich or very, very, very poor. Either way, you won't benefit. (Also wow the first ever english question with only 1 answer I lucked out)
I would go with A. The others seem more scientific and simply answered. For an essay you're gonna want something with multiple answers. So I'd for sure go with A.