It Comes to Quality of Life

it comes to quality of life:

A) studies in the U.S. over the past 50 years have shown that less than half of the population considers their life "satisfying" or "very satisfying."
B) more affluent countries show larger percentages of satisfied or very satisfied people than less affluent countries.
C) older adults report a lower quality of life than middle-age adults because they tend to compare themselves to how they were when they were younger.
D) the strongest predictor is personality.