A Man Moves from a Large City to a Small

Multiple Choice

A man moves from a large city to a small town.  In the small town he seems like a very different person than the person he was in the big city.  For instance, he is more polite in the small town than he was in the big city.  This could be because

A) the costs of his being impolite are higher in the big city than in the small town.
B) the costs of his being impolite are higher in the small town than in the big city.
C) he is a happier person in the large city and it could be that happier people are more polite.
D) the costs of his being impolite are the same in the big city as in the small town.