Cross-Section Studies Comparing People Across Different Income Groups in Each

Cross-section studies comparing people across different income groups in each country in any given year suggest that rich people are, on average:

A) less happy than poor people but not as happy as people with average income.
B) happier than poor people.
C) about as happy as poor people; money seems to make little difference.
D) less happy than poor people, but happier than middle class people.