## Core Concept
The question assesses knowledge of nephrotoxicity associated with various antibiotics, which is crucial for safe prescribing practices, especially in patients with pre-existing renal conditions. Nephrotoxicity refers to the potential of certain substances to cause damage to the kidneys.

## Why the Correct Answer is Right
Among the given options, **Aminoglycosides (e.g., Gentamicin)** are well-known for their nephrotoxic potential. They can cause renal damage through various mechanisms, including direct toxicity to renal tubular cells and ischemia due to vasoconstriction. **Vancomycin**, a glycopeptide antibiotic, can also exhibit nephrotoxicity, though its incidence is generally lower than that of aminoglycosides. **Amphotericin B**, an antifungal agent, is notably nephrotoxic, causing renal vasoconstriction and direct damage to renal tubules. **Ceftriaxone**, a third-generation cephalosporin, is not commonly associated with nephrotoxicity compared to the other options listed.

## Why Each Wrong Option is Incorrect
- **Option A:** If Aminoglycosides (e.g., Gentamicin) are listed here, they are incorrect because they are known to be nephrotoxic.
- **Option B:** If Vancomycin is listed, it is incorrect because, although less nephrotoxic than aminoglycosides or amphotericin B, it still carries a risk of nephrotoxicity.
- **Option D:** If Amphotericin B is listed, it is incorrect because it has significant nephrotoxic potential.

## Clinical Pearl / High-Yield Fact
A key point to remember is that when using potentially nephrotoxic antibiotics, monitoring renal function through serum creatinine and electrolytes is essential. For aminoglycosides, this monitoring is critical to prevent nephrotoxicity, and once-daily dosing regimens are often used to minimize this risk.

## Correct Answer Line
**Correct Answer: C. Ceftriaxone**.