Correct Answer: A

Rationale: The correct answer is A: A normal finding. The Darwin tubercle is a small, painless, bony nodule at the helix of the ear and is considered a normal anatomical variation. It is present in a significant portion of the population, regardless of age. It does not indicate any pathology or abnormality. Choices B, C, and D are incorrect because the presence of a Darwin tubercle is not indicative of any abnormality, and it is not limited to older adults.

Correct Answer: A

Rationale: The correct answer is A: Positive family history. Pernicious anemia is an autoimmune condition where the body attacks its own intrinsic factor, leading to vitamin B12 deficiency. Genetic predisposition plays a significant role in the development of pernicious anemia. Family history is a key risk factor as individuals with a family history of pernicious anemia are more likely to develop the condition. Summary of why the other choices are incorrect: B: Infectious agents or toxins do not directly cause pernicious anemia, although they can lead to other types of anemia. C: Acute or chronic blood loss can result in iron-deficiency anemia, not pernicious anemia. D: Inadequate dietary intake of vitamin B12 can lead to vitamin B12 deficiency anemia, but pernicious anemia specifically involves the body's inability to absorb B12 due to intrinsic factor deficiency, not dietary intake alone.

Correct Answer: D

Rationale: The correct answer is D: To wash hands frequently. This is important in rhinitis prevention as it helps reduce the spread of viruses and bacteria that can trigger or exacerbate symptoms. Washing hands removes potential allergens and irritants, reducing the risk of rhinitis flare-ups. Choice A is incorrect as blowing the nose is necessary to clear mucus and alleviate symptoms. Choice B is irrelevant to rhinitis prevention. Choice C is not directly related to preventing rhinitis.

Correct Answer: B

Rationale: The correct answer is B: IgE. IgE is specific to allergic responses as it binds to mast cells and basophils, triggering the release of histamine and other inflammatory mediators. IgA is more involved in mucosal immunity, IgG is involved in long-term immunity and opsonization, and IgM is the primary antibody in the primary immune response. IgB is not a known immunoglobulin. Therefore, IgE is the specific immunoglobulin associated with allergic responses due to its role in mediating hypersensitivity reactions.

Correct Answer: B

Rationale: The correct answer is B: Monitor for fatigue, muscle weakness, restlessness, and flushed skin. The patient is at risk for dehydration due to the combination of high temperature, age, and thiazide diuretic use. Thiazide diuretics can lead to electrolyte imbalances, including hypokalemia, which can cause symptoms such as muscle weakness and fatigue. Monitoring for signs of dehydration and electrolyte imbalances is crucial in this scenario to prevent complications. A: Making sure he drinks 8 glasses of water a day is not the priority as he is already at risk for dehydration and electrolyte imbalances. C: Hyperchloremia is not a common concern in this scenario based on the given lab values. D: Neurologic changes may occur in severe cases of electrolyte imbalances but monitoring for physical symptoms such as fatigue and muscle weakness is more relevant at this stage.