Correct Answer: A

Rationale: The correct answer is A: Right lower quadrant cramping. Crohn's disease commonly presents with abdominal pain, particularly in the right lower quadrant. Choice B, severe bloody diarrhea, is more characteristic of ulcerative colitis, another type of inflammatory bowel disease. Choice C, nausea and vomiting, are not typical symptoms of Crohn's disease. Choice D is incorrect as Crohn's disease can affect any part of the gastrointestinal tract, not just the rectum.

Correct Answer: C

Rationale: In a 60-year-old man presenting with painless hematuria, the next step in the evaluation should be cystoscopy. Cystoscopy is recommended to assess the cause of hematuria, particularly to rule out bladder cancer, which is more common in older individuals. Urinalysis (Choice A) can provide initial information but may not definitively diagnose the underlying cause. Renal ultrasound (Choice B) and intravenous pyelogram (Choice D) are imaging studies that may be considered later in the evaluation process but are not the initial step for painless hematuria.

Correct Answer: C

Rationale: The correct answer is C, aortic dissection. Aortic dissection is characterized by sudden, severe chest pain that can radiate to the back. The discrepancy in blood pressure between the arms (higher in the right arm) is known as a 'pulse deficit' and is a classic finding in aortic dissection. This condition involves a tear in the inner layer of the aorta, leading to the abnormal flow of blood within the aortic wall. Acute myocardial infarction (choice A) presents with chest pain but typically does not cause discrepancies in blood pressure between arms. Pulmonary embolism (choice B) usually presents with chest pain and difficulty breathing but does not cause unequal blood pressures in the arms. Pericarditis (choice D) can cause chest pain exacerbated by breathing or lying down, but it does not typically lead to differences in blood pressure between arms.

Correct Answer: B

Rationale: The correct answer is B because sudden onset of behavioral changes is a typical symptom of delirium. Delirium is characterized by an acute and fluctuating disturbance in attention, awareness, and cognition. Choice A is incorrect because delirium is not a normal part of aging. Choice C describes memory issues, which can be seen in delirium but are less specific than sudden behavioral changes. Choice D, while it mentions the patient's independence, does not directly support the diagnosis of delirium.

Correct Answer: D

Rationale: The correct answer is D. Hemangiomas, congenital dermal melanocytosis (i.e., Mongolian spots), and macular stains are birthmarks that usually fade or regress as the child gets older. Hemangiomas are vascular birthmarks that often shrink and fade over time. Congenital dermal melanocytosis (Mongolian spots) are blue-gray birthmarks commonly found on the lower back and buttocks of infants, which typically fade by adolescence. Macular stains, also known as salmon patches, are pink or red birthmarks that usually fade within the first few years of life. Choice D is correct because all the mentioned birthmarks tend to diminish as the child grows, unlike choices A, B, and C which do not fade or regress with age.