**Core Concept**
Glutathionation is a type of conjugation reaction where a glutathione molecule is added to a drug, making it more water-soluble and easier to excrete from the body. This process is an important mechanism of drug metabolism, particularly for drugs that are highly reactive or toxic.

**Why the Correct Answer is Right**
Fosfomycin is a broad-spectrum antibiotic that undergoes glutathionation as part of its metabolic pathway. This reaction involves the transfer of a glutathione molecule to the fosfomycin molecule, resulting in the formation of a more water-soluble conjugate that can be easily excreted by the kidneys. The glutathionation of fosfomycin is an important mechanism for its detoxification and elimination from the body.

**Why Each Wrong Option is Incorrect**
* **Option A:** Benzodiazepines are primarily metabolized by oxidative reactions, such as hydroxylation and demethylation, rather than glutathionation.
* **Option B:** Dapsone is metabolized by acetylation, a different type of conjugation reaction, rather than glutathionation.
* **Option D:** Nicotinic acid (niacin) is metabolized by oxidative reactions, such as hydroxylation, rather than glutathionation.

**Clinical Pearl / High-Yield Fact**
Glutathionation is an important mechanism for the detoxification of reactive or toxic compounds, including some drugs. This process helps to protect the body from the harmful effects of these compounds and is an important aspect of pharmacokinetics.

**✓ Correct Answer: C. Fosfomycin**