Correct Answer: B

Rationale: Bones store electrolytes and act as a reservoir, maintaining a balance of essential minerals like calcium and phosphate. The correct pair in this context is 'Bone - Nails.' Choices A, C, and D are incorrect because the brain, kidneys, liver, and pancreas perform other functions in the body and are not primarily responsible for storing electrolytes.

Correct Answer: B

Rationale: In acute respiratory failure, hypoxemia (low blood oxygen) and hypercapnia (high blood carbon dioxide) are commonly observed. Choice A is incorrect because alkalosis (high pH) and hyperventilation are not typically seen in acute respiratory failure. Choice C is incorrect as it mentions alkalosis and high potassium, which are not characteristic of acute respiratory failure. Choice D is also incorrect because elevated sodium and acidosis are not typically associated with acute respiratory failure.

Correct Answer: C

Rationale: The correct answer is C: PH 7.40, PaCO2 40 mm Hg, PaO2 90 mm Hg, HCO3 24 mEq/L. These values represent a balanced state for arterial blood gas. Choice A has lower than normal PH and HCO3 levels and higher PaCO2 and lower PaO2 levels. Choice B has higher than normal PH and HCO3 levels, lower PaCO2, and a normal PaO2 level. Choice D has a significantly lower PH and PaO2 level, normal HCO3 level, and low PaCO2 level, indicating an acidic state with impaired oxygenation.

Correct Answer: C

Rationale: Correct Answer: The nurse should inform the patient that finasteride may take several months to improve symptoms of BPH. It is essential for patients to understand the delayed onset of action to manage their expectations and compliance. Choice A is incorrect because there is no significant interaction between finasteride and over-the-counter antacids. Choice B is incorrect as finasteride is more commonly associated with decreased libido rather than increased libido. Choice D is incorrect as finasteride is known to reduce hair growth rather than increase it.

Correct Answer: A

Rationale: The correct answer is A: Bone marrow. B cells are originally derived from cells of the bone marrow. Bone marrow is the primary site where B cells develop and mature. Lymph nodes (choice B), gut-associated lymphoid tissue (choice C), and the thymus (choice D) are involved in the immune response but are not the primary site of origin for B cells.