Some of the most convincing evidence that helps to explain the observed increase in the incidence of anorexia nervosa and bulimia nervosa over the past half century is
a. improved diagnostic and reporting practices.
b. concurrent increases in the rate of depression.
c. the generally improved health of the society and an increased emphasis on diet and exercise.
d. a strong relationship between exposure to media images depicting the thin-ideal body and body image concerns in women.

Some of the most convincing evidence that helps to explain the observed increase in the incidence of anorexia nervosa and bulimia nervosa over the past half century is "concurrent increases in the rate of depression."

Explanation:

For us to be able to understand this question and its answer we need to define the key terms involved;

Anorexia nervosa and bulimia nervosa these are simply eating disorder. people tend to have eating disorder when they are always depressed.