**Core Concept**
Antioxidants are molecules that prevent oxidative damage by neutralizing free radicals, thereby protecting cells from oxidative stress. In the context of pharmacology and medicine, antioxidants are crucial in mitigating the effects of oxidative stress, which is implicated in various diseases, including cardiovascular disease, cancer, and neurodegenerative disorders.

**Why the Correct Answer is Right**
Glutathione, vitamin C, and vitamin E are well-known antioxidants that scavenge free radicals and prevent oxidative damage. Glutathione, in particular, is a tripeptide composed of cysteine, glycine, and glutamic acid that plays a critical role in cellular antioxidant defenses. Vitamin C, a water-soluble vitamin, is a potent antioxidant that neutralizes free radicals in aqueous environments. Vitamin E, a lipid-soluble vitamin, protects cell membranes from oxidative damage by scavenging free radicals that can cause lipid peroxidation.

**Why Each Wrong Option is Incorrect**
* **Option A:** is not a known antioxidant.
* **Option B:** is a pro-oxidant, which can actually contribute to oxidative stress.
* **Option C:** has no direct antioxidant properties.

**Clinical Pearl / High-Yield Fact**
Antioxidants are not a replacement for a healthy lifestyle, but they can complement other preventive measures, such as a balanced diet, regular exercise, and stress management, to mitigate oxidative stress and reduce the risk of chronic diseases.

**Correct Answer: D. Glutathione, vitamin C, and vitamin E.**