Level of happiness tends to fluctuate around

A) a happiness set point.
B) predictable levels.
C) heritable levels.
D) relative deprivation.

Research has suggested that individuals have a happiness set point, meaning they tend to have a stable level of happiness that they fluctuate around. This set point is influenced by both genetic and environmental factors, but it is not necessarily predictable or heritable. Relative deprivation refers to the idea that individuals compare themselves to others and may feel less satisfied or happy if they perceive themselves to be worse off than others, but this is not the same as the fluctuation of happiness around a set point.