The nurse is providing care for a client with a fluid imbalance. The nurse explains that in the body, areas with high concentration of solutes naturally and passively shift to areas of lower concentration. The nurse is describing which process?

Choice A reason: Excessive stomach acid secretion is not the correct answer because it is not a diagnostic test, but a possible cause of peptic ulcer disease. Peptic ulcers are sores that develop in the lining of the stomach or duodenum due to damage from stomach acid and digestive enzymes.

Choice B reason: An incompetent pyloric sphincter is not the correct answer because it is not a diagnostic test, but a possible complication of peptic ulcer disease. The pyloric sphincter is a muscular valve that controls the passage of food from the stomach to the small intestine. If it becomes damaged or weakened, it can cause gastric outlet obstruction, which is a blockage of the stomach.

Choice C reason: A metabolic acid-base imbalance is not the correct answer because it is not a diagnostic test, but a possible consequence of peptic ulcer disease. Peptic ulcers can cause bleeding, perforation, or gastric outlet obstruction, which can affect the acid-base balance of the body. For example, vomiting can cause metabolic alkalosis, which is a condition where the blood is too alkaline.

Choice D reason: An infection with Helicobacter pylori is the correct answer. Helicobacter pylori is a type of bacteria that can infect the stomach and duodenum and cause inflammation and ulcers. It is the most common cause of peptic ulcer disease. The health care provider can order a diagnostic test to detect the presence of Helicobacter pylori in the client's stomach or blood, such as a urea breath test, a stool antigen test, or a blood antibody test.

Choice A reason: This is the correct answer because weighing 28% above ideal body weight is a sign of obesity. Ideal body weight is an estimate of the weight that corresponds to the lowest mortality for a given height and gender. Obesity is defined as having a body weight that is 20% or more above ideal body weight.

Choice B reason: This is not the correct answer because having a waist circumference of 81.3 cm (32 in) is not a manifestation of obesity. Waist circumference is a measure of abdominal fat, which is associated with increased health risks. However, the cut-off point for waist circumference varies by gender and ethnicity. For women, a waist circumference of more than 88 cm (35 in) is considered high.

Choice C reason: This is not the correct answer because having a BMI of 28 is not a manifestation of obesity. BMI is a measure of body mass index, which is calculated by dividing weight in kilograms by height in meters squared. BMI is used to classify weight status and health risks. For adults, a BMI of 18.5 to 24.9 is considered normal, 25 to 29.9 is considered overweight, and 30 or more is considered obese.

Choice D reason: This is not the correct answer because having a body fat of 22% is not a manifestation of obesity. Body fat is a measure of the percentage of fat in the body, which is determined by various methods such as skinfold thickness, bioelectrical impedance, or underwater weighing. Body fat is influenced by age, gender, and physical activity. For women, a body fat of 21 to 33% is considered normal, 33 to 39% is considered high, and more than 39% is considered very high.