**Core Concept**
Disinfectants are categorized based on their efficacy against microorganisms, with high-level disinfectants capable of killing all microorganisms, including bacterial spores. Intermediate-level disinfectants, on the other hand, are effective against all non-enveloped viruses, most bacteria, and some fungi, but may not kill bacterial spores.

**Why the Correct Answer is Right**
Intermediate-level disinfectants work by disrupting the cell membranes of microorganisms, ultimately leading to cell lysis and death. Examples of intermediate-level disinfectants include quaternary ammonium compounds (quats) and hydrogen peroxide. These agents are commonly used in healthcare settings for disinfecting surfaces and equipment.

**Why Each Wrong Option is Incorrect**
**Option A:** High-level disinfectants are typically used for heat-sensitive equipment and can kill all microorganisms, including bacterial spores.
**Option B:** Sterilants, such as ethylene oxide, are used to eliminate all forms of microbial life, including bacterial spores.
**Option C:** Antimicrobial agents, such as bleach, are effective against a broad spectrum of microorganisms, but may not be suitable for all surfaces or equipment.

**Clinical Pearl / High-Yield Fact**
When selecting a disinfectant, it's essential to consider the type of microorganism being targeted, as well as the surface or equipment being disinfected.

**Correct Answer: C. Hydrogen peroxide.**