**Core Concept**
The glomerular filtration rate (GFR) is the rate at which fluid is filtered through the glomeruli of the kidneys. It is a key indicator of kidney function. Various factors can influence GFR, including blood pressure, kidney disease, and certain medications.

**Why the Correct Answer is Right**
Since the actual options and correct answer are not provided, a general explanation is given. Typically, conditions or substances that decrease GFR do so by either reducing blood flow to the glomeruli or increasing the resistance to filtration. For example, **angiotensin II** can decrease GFR by constricting the efferent arterioles, while **non-steroidal anti-inflammatory drugs (NSAIDs)** can reduce GFR by inhibiting prostaglandin synthesis, which is important for maintaining renal blood flow.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect if it represented a condition or substance known to decrease GFR, such as kidney disease or certain medications.
**Option B:** Similarly, would be incorrect if it represented another factor that reduces GFR.
**Option C:** Would also be incorrect for similar reasons as options A and B.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that any condition or substance that reduces renal blood flow or increases the resistance to glomerular filtration will decrease the GFR. This includes **dehydration**, **heart failure**, and **nephrotoxic substances**.

**Correct Answer:**