To qualify for a diagnosis of bulimia nervosa, what must be TRUE of the compensatory behaviors displayed?

A) They must occur.

B) They must involve vomiting.

C) They must effectively cause weight loss.

D) They must cause pathological changes in the body

A) They must occur

Explanation:

Bulimia disorder is a type of eating disorder in which an individual engages in bingeing, which involves eating a large amount of food without being able to control ones appetite. The individual often becomes worried and preoccupied with his or her body weight, and therefore engages in compensatory behaviors that are unhealthy in order to lose weight and also to relieve the guilt they feel. Compensatory behavior of someone suffering from this disorder is not just restricted to use of laxative to induce vomiting. These also include fasting, excessive exercise, misuse of weight-loss supplements or diuretics etc.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.