Although We Know That Money Can't Buy Happiness, Research in Britain

Although we know that money can't buy happiness, research in Britain and the United States suggests that:

A) unskilled and partly skilled workers at the bottom of the pay scale are happier than other workers.
B) skilled manual workers from lower middle pay scale are happier than better-paid, non-manual, professional workers.
C) middle-class workers are happier than their wealthy counterparts.
D) the wealthy express the least level of happiness with their standard of living.