Correct Answer: C

Rationale: The correct answer is C: 'A malignant growth of white blood cells.' Leukemia is a type of cancer that affects the blood and bone marrow, leading to an overproduction of abnormal white blood cells. These cells are malignant and impair the normal function of healthy blood cells. Choices A, B, and D are incorrect because leukemia does not involve skin cells or benign growths; instead, it specifically refers to the abnormal proliferation of white blood cells.

Correct Answer: A

Rationale: In this scenario, the most crucial action for the nurse to take is to observe the patient taking the medications. This ensures that the patient is actually consuming the prescribed antitubercular drugs, addressing the issue of nonadherence directly. Administering the medications parenterally (intravenously or intramuscularly) is not necessary unless there are specific medical reasons requiring this route of administration. Instructing the family on the medication regimen is important for support but may not directly address the patient's nonadherence. Counting the number of tablets in the bottle daily is not as effective as directly observing the patient taking the medications to ensure compliance.

Correct Answer: C

Rationale: The correct answer is C: Air trapping in the alveoli. A barrel chest in emphysema results from the hyperinflation of the lungs due to air trapping in the alveoli. This leads to increased anteroposterior diameter of the chest. Choices A, B, and D are incorrect. Peripheral edema is swelling caused by fluid retention in tissues, not associated with a barrel chest in emphysema. Bacterial infections in the lungs can lead to conditions like pneumonia but do not directly cause a barrel chest. Muscle atrophy of the diaphragm could affect breathing mechanics but is not specifically linked to the development of a barrel chest in emphysema.

Correct Answer: D

Rationale: The correct answer is D: Metabolic acidosis. Severe diarrhea can lead to metabolic acidosis because the loss of bicarbonate ions in the stool results in an overall decrease in the body's bicarbonate levels. Respiratory acidosis (choice A) is caused by retention of carbon dioxide, usually due to inadequate alveolar ventilation. Metabolic alkalosis (choice B) is characterized by elevated pH and bicarbonate levels, usually caused by conditions like vomiting. Respiratory alkalosis (choice C) is a condition of low blood carbon dioxide levels and high pH, often due to hyperventilation.

Correct Answer: B

Rationale: When a patient is receiving amphotericin B, which is known to cause renal toxicity, they are most likely to require magnesium supplementation. Amphotericin B can lead to renal loss of magnesium, potassium, and calcium. Magnesium is an essential mineral that plays a vital role in various physiological functions, and its levels need to be monitored and supplemented when necessary. Chloride, glucose, and sodium are not typically supplemented in the context of amphotericin B therapy for a serious fungal infection.