**Core Concept**
Renal function failure can be evaluated using various radiotracers that assess different aspects of kidney function, including glomerular filtration rate (GFR), tubular function, and renal blood flow.

**Why the Correct Answer is Right**
The correct answer is **D. All** because each option evaluates a different aspect of renal function. **DTPA (A)** is a glomerular filtration rate (GFR) marker, which is useful for assessing the function of the glomeruli. **DMSA (B)** is a static renal imaging agent that provides information about the renal cortex, useful for detecting cortical scarring or abnormalities. **Iodohippurate (C)** is a tubular function marker that assesses the ability of the renal tubules to reabsorb or secrete substances. Therefore, all three options provide valuable information about different aspects of renal function.

**Why Each Wrong Option is Incorrect**
- **Option A:** While DTPA is a useful marker for GFR, it does not provide information about tubular function or renal blood flow.
- **Option B:** Similarly, DMSA provides information about the renal cortex but does not assess GFR or tubular function.
- **Option C:** Iodohippurate specifically assesses tubular function but does not provide information about GFR or renal blood flow.

**Clinical Pearl / High-Yield Fact**
When evaluating renal function, it's essential to choose the radiotracer that best matches the clinical question. For example, DTPA is useful for monitoring changes in GFR over time, while DMSA is more useful for detecting cortical abnormalities.

**Correct Answer:**
✓ Correct Answer: D. All