**Core Concept**
Sporicidal agents are used to eliminate spores, highly resistant forms of bacteria, from the environment. These agents are crucial in the sterilization of medical equipment and in the treatment of infections caused by spore-forming bacteria.

**Why the Correct Answer is Right**
The correct answer is likely a substance or agent that is not effective against spores. Sporicidal agents work by disrupting the spore's outer coat, allowing water to penetrate and ultimately leading to the death of the spore. Examples of sporicidal agents include hydrogen peroxide, glutaraldehyde, and formaldehyde.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely a substance that is effective against spores, such as hydrogen peroxide or formaldehyde.

**Option B:** This option is likely a substance that is not effective against spores, such as chlorhexidine or povidone-iodine, which are bactericidal but not sporicidal.

**Option C:** This option is likely a substance that is effective against spores, such as glutaraldehyde or ethylene oxide.

**Clinical Pearl / High-Yield Fact**
When selecting a sporicidal agent, it's essential to consider the type of spore-forming bacteria present and the level of resistance required. For example, formaldehyde is effective against Bacillus anthracis spores, while hydrogen peroxide is effective against Clostridium difficile spores.

**Correct Answer: B. Chlorhexidine is a broad-spectrum antimicrobial agent, but it is not effective against spores.**