Which of the following is true about natural selection I. it is faster than adaptation
II. it is about the survival of the fittest
III. it creates variation within species and

The correct answer is vomiting that may have further resulted in dehydration and electrolyte imbalance.

Explanation:

An extreme and potentially considered life-threatening eating disorder known as bulimia or bulimia nervosa refers to a condition in which an individual develops a habit of consuming large amounts of food and exhibits no control overeating. However, it also attempts to shed away the extra added calories in a manner, which is not considered healthy, that is, by purging or vomiting.  

In the given case, the client has a history of bulimia nervosa would have been exhibiting purging behaviors like vomiting that may have further resulted in the conditions like dehydration and electrolyte imbalance. In the given case, the dry mucous membranes show dehydration, and restlessness and hallucinations could be the signs of electrolyte imbalance.