Which of the following best describes subjective well-being?

a. it refers to the impersonal, deepest layer of the unconscious mind, shared by all human beings because of their common ancestral past.
b. It is the belief that one can accomplish a given goal or task and produce positive change.
c. It refers to the general expectation that good things are more likely than bad things to occur in the future.
d. It is a person's assessment of his or her own level of positive affect relative to negative affect and an evaluation of his or her life in general.