Correct Answer: B

Rationale: The correct answer is B: Underexcretion of uric acid. Gouty arthritis is primarily caused by the underexcretion of uric acid, leading to its accumulation in joints and subsequent crystallization. Choices A, C, and D are incorrect as they do not directly relate to the pathophysiology of gout. Destruction of proteoglycans, overexcretion of uric acid, and increased absorption of uric acid are not primary causes of gouty arthritis.

Correct Answer: D

Rationale: Confabulation, a common symptom in dementia, involves filling in memory gaps with fabricated stories rather than intentionally pretending to be someone else (Choice B), denying confusion by being jovial (Choice A), or rationalizing various behaviors (Choice C). Confabulation is not a deliberate act but a memory error that results in the creation of false memories.

Correct Answer: B

Rationale: HbAS indicates sickle cell trait, not full-blown sickle cell anemia. Choice A is incorrect because HbAS indicates the presence of the sickle cell trait. Choice C is incorrect as sickle cell anemia is characterized by HbSS, not HbAS. Choice D is incorrect as thalassemia is a different type of hemoglobin disorder not indicated by HbAS.

Correct Answer: B

Rationale: Bullous impetigo is the correct answer because it is caused by a Staphylococcus aureus toxin that leads to exfoliation and the formation of large blisters. Herpes simplex I virus (Choice A) causes cold sores and is not associated with exfoliation and blister formation. Necrotizing fasciitis (Choice C) is a severe skin infection involving the deeper layers of skin and subcutaneous tissues, typically caused by bacteria such as Streptococcus or Clostridium species, not Staphylococcus aureus. Cellulitis (Choice D) is a common bacterial skin infection, but it does not involve exfoliation and blister formation as seen in bullous impetigo.

Correct Answer: C

Rationale: Dark urine is a classic symptom of rhabdomyolysis. When muscle breakdown occurs, myoglobin is released into the bloodstream and filtered by the kidneys, leading to dark urine. Paresthesias (choice A) refer to abnormal sensations like tingling or numbness and are not typically associated with rhabdomyolysis. Bone pain (choice B) is not a prominent symptom of rhabdomyolysis. Diarrhea (choice D) is not a common complaint in rhabdomyolysis cases and is not directly related to muscle breakdown.