The most reliable screening test for Primary Aldosteronism is

Correct Answer: C

Rationale: Plasma aldosterone-to-renin ratio (ARR) screens primary aldosteronism best high aldosterone, low renin (e.g., adenoma) flags it reliably. Serum potassium (hypokalemia) is suggestive non-specific. Urine aldosterone is diagnostic, not screening cumbersome. Adrenal vein sampling confirms laterality post-screening. ARR's sensitivity distinguishes it, critical for early detection, unlike secondary or invasive tests.

Correct Answer: C

Rationale: Alpha1c isn't a recognized receptor misnomer; Alpha1a, Alpha1b, and Alpha1d mediate LUTS (e.g., BPH). Alpha1a dominates prostate/bladder neck obstruction. Alpha1d affects detrusor irritative. Alpha1b is vascular less LUTS-specific. Non-existent Alpha1c distinguishes it, key to receptor pharmacology, unlike active mediators.

Correct Answer: A

Rationale: The nephron ends at the collecting duct, which drains into the renal papilla, unlike the distal convoluted tubule (preceding), glomerulus (start), or papilla (not part). This distinguishes the nephron's final segment, critical for urine concentration, contrasting with earlier structures.

Correct Answer: B

Rationale: GFR averages 180 L/day (125 mL/min × 1440 min), not 10 L, 1.5 L, or 1 mL/min (misunits). This quantifies filtration capacity, critical for renal function assessment, contrasting with incorrect scales.

Correct Answer: D

Rationale: Amino acid reabsorption in PCT uses active transport (Na+-linked), not albumin/creatinine (filtration) or water (osmosis). This distinguishes active mechanisms, critical for nutrient retention, contrasting with passive processes.