Okay, so the user wants me to create a detailed explanation for a multiple-choice question about the glomerular filtration rate (GFR). Let me start by recalling the core concept here. GFR is a measure of kidney function, right? It's the rate at which the glomeruli filter blood. The key points would be that GFR is the volume of fluid filtered from the glomerular capillaries into the Bowman's capsule per unit time. It's influenced by factors like hydrostatic pressure, oncotic pressure, and the filtration barrier's permeability.

Now, the correct answer should explain that GFR is the volume of filtrate formed per minute by both kidneys. I need to make sure that the explanation includes the normal range, like 90-120 mL/min/1.73m², and mention that it's measured using creatinine clearance or estimated via formulas like eGFR. Also, important to note that GFR is a critical indicator of renal function and is used to stage chronic kidney disease.

For the wrong options, common mistakes might include confusing GFR with other renal parameters like renal plasma flow or urine output. For example, if an option says GFR is the amount of urine produced, that's incorrect because urine output is much lower due to reabsorption. Another wrong option might mention filtration pressure directly, but GFR is the result of the net filtration pressure, not the pressure itself. Also, some might confuse GFR with the filtration coefficient, which is a component in the calculation but not the rate itself.

The clinical pearl here is to remember that GFR is age-dependent and decreases with age, so a lower GFR in elderly patients might not indicate disease. Also, using eGFR based on serum creatinine is standard for assessing kidney function. High-yield fact: GFR is the best overall measure of kidney function, and a sustained decrease indicates chronic kidney disease.

I need to structure each section as per the user's instructions: Core Concept, Why Correct, Why Wrong Options are Wrong, Clinical Pearl, then the Correct Answer. Keep it concise, use bold for key terms, and avoid markdown except where specified. Let me check the character count to stay under 2500. Make sure each section is clear and addresses the required points. Also, ensure that the explanations are accurate and use precise terminology.

**Core Concept**
Glomerular filtration rate (GFR) measures the volume of fluid filtered from the glomerular capillaries into Bowman’s space per unit time. It reflects renal function and is determined by the balance of hydrostatic and oncotic pressures across the glomerular filtration barrier. Normal GFR is **90–120 mL/min/1.73 m²** in healthy adults.

**Why the Correct Answer is Right**
GFR quantifies the kidneys’ ability to filter waste from blood. It is calculated using the formula: **GFR = (Urine concentration × Urine flow rate) / Plasma concentration** (inulin clearance is the gold standard). Clinically, estimated GFR (eGFR) derived from serum creatinine is widely used. A decline in GFR indicates impaired renal function, staging chronic kidney disease (CKD).

**Why Each Wrong Option is Incorrect**
**Option A:** Confuses GFR with renal plasma flow (RPF), which measures total plasma volume reaching

✓ Correct Answer: B. 125 ml/min