Correct Answer: B

Rationale: The correct answer is B: Prepare the client for emergency surgery. Aortic dissection is a life-threatening emergency that often necessitates immediate surgical intervention to prevent rupture and further complications. Administering antihypertensive medications (choice A) may be necessary but is not the priority over surgical intervention. While maintaining blood pressure with intravenous fluids (choice C) is important, the urgent need for surgery takes precedence. Monitoring urine output (choice D) is essential for assessing renal function but is not the priority in this critical situation.

Correct Answer: B

Rationale: The correct answer is B: 'Use of nitrates.' Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both act as vasodilators, and their combined use can lead to a dangerous drop in blood pressure. Choices A, C, and D are incorrect because having a history of hypertension, using antihypertensive medications, or having a history of peptic ulcer disease are not key contraindications for sildenafil use.

Correct Answer: B

Rationale: The correct answer is B because consistent intake of prescribed drugs is crucial for curing tuberculosis. By emphasizing the necessity of following the treatment plan, the patient is more likely to achieve a successful outcome. Choice A is incorrect because it focuses on the risk of adverse effects rather than the primary goal of TB cure. Choice C is incorrect as it does not address the issue of inconsistent drug intake. Choice D is also incorrect as it introduces a different treatment (antiretrovirals) not relevant to latent tuberculosis.

Correct Answer: C

Rationale: In Guillain-Barre syndrome, the destruction of myelin leads to axonal damage. If remyelination does not occur, the axon will eventually degenerate and die, impacting nerve function. Choice A is incorrect because the destruction of myelin does not affect Schwann cell production. Choice B is incorrect as the lack of myelin directly affects the conduction of nerve impulses, not the axonal transport system. Choice D is incorrect as a deficit of myelin does not predispose the client to infections by potential pathogens.

Correct Answer: B

Rationale: DiGeorge syndrome is caused by a congenital lack of thymic tissue, which plays a crucial role in T cell development and maturation, leading to immune deficiency. Choice A is incorrect because DiGeorge syndrome primarily affects T cells, not B cells. Choice C is incorrect as it is too broad and not specific to the thymus. Choice D is incorrect as selective IgG deficiency is a different condition unrelated to DiGeorge syndrome.