**Core Concept**
Category-B bioterrorism agents are moderately easy to disseminate, result in moderate morbidity rates and low mortality rates, and require specific enhancements for diagnostic capacity and enhanced disease surveillance. These agents include toxins such as botulinum toxin and ricin.

**Why the Correct Answer is Right**
Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum, which causes botulism. It is classified as a Category-B bioterrorism agent due to its ease of production, dissemination, and relative ease of treatment. Botulinum toxin works by inhibiting the release of acetylcholine, a neurotransmitter responsible for muscle contraction, leading to flaccid paralysis.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect as it is not a bioterrorism agent.

**Option B:**
This option is incorrect as it is a Category-A bioterrorism agent.

**Option D:**
This option is incorrect as it is a Category-C bioterrorism agent.

**Clinical Pearl / High-Yield Fact**
Botulinum toxin can be inactivated with heat, making it susceptible to destruction through proper cooking and pasteurization of food products.

**Correct Answer: C. Botulinum toxin**