It is an example of, theme. Theme would tell you how the mood is set. <em />It's not symbolism, because there was no object to describe that moment, or any past moment. Hope this helps!
The answer is C, as the story is at the time of Prohibition in the United States.
The answer is A, when looking for the thesis, most times it will be the first sentence.
1. One paragraph focuses on one subject and the next focuses on a different one that's related to the first one.
2. Sentences have structures like "____ is like this, while/but/however ____ is like that".
3. Sentences say something to the effect of "Both ____ are like this".
2 and 3 are also easy ways to identify compare and contrast essays if you simply apply this logic to the thesis statement in the introductory paragraph.