**Core Concept**
Levamisole is an anthelminthic medication that also possesses immunomodulatory properties. It acts by stimulating the immune system, particularly through the activation of macrophages and the enhancement of cell-mediated immunity.

**Why the Correct Answer is Right**
Levamisole exerts its immunomodulatory effects by binding to nicotinic acetylcholine receptors on immune cells, such as macrophages and T lymphocytes. This binding leads to an increase in the production of cytokines, which are signaling molecules that facilitate communication between immune cells. As a result, levamisole enhances the body's immune response, making it more effective against infections and diseases.

**Why Each Wrong Option is Incorrect**
**Option A:** Albendazole is a broad-spectrum anthelminthic medication, but it does not have significant immunomodulatory effects. It is primarily used to treat parasitic infections caused by worms.
**Option C:** Mebendazole is another anthelminthic medication that is similar to albendazole in its mechanism of action. It does not possess immunomodulatory properties.
**Option D:** Piperazine is an anthelminthic medication that works by causing muscle paralysis in worms, leading to their expulsion from the body. It does not have any significant immunomodulatory effects.

**Clinical Pearl / High-Yield Fact**
Levamisole is often used as an adjunct therapy in patients with immunocompromised conditions, such as HIV/AIDS, to enhance their immune response and reduce the risk of opportunistic infections.

**✓ Correct Answer: B. Levamisole**