Darius conducted an observational study to learn how a successful career affects happiness. He surveyed 600 people in his hometown and found that 75% say the more success they have in their career, the more happiness they experience. Choose from the following the conclusion that Darius can draw from his study.
A.) A successful career is the only factor that contributes to happiness.
B.) A successful career results in happiness.
C.) Happiness results in a successful career.
D.) There may be a link between a successful career and happiness.
