**Core Concept**
Heterochromia iridis refers to a condition where there is an uneven distribution of melanin in the iris, resulting in a patchy or multi-colored appearance. This condition can be caused by various factors, including trauma, genetic conditions, or certain medications.

**Why the Correct Answer is Right**
Epinephrine, an adrenergic agonist used in the treatment of glaucoma, can cause heterochromia iridis as a side effect. This is due to the stimulation of melanin production in the iris, leading to an uneven distribution of pigment. Epinephrine increases melanin production by activating the enzyme tyrosinase, which is responsible for converting the amino acid tyrosine into melanin.

**Why Each Wrong Option is Incorrect**
* **Option A:** Prostaglandin analogs, such as latanoprost, are a common class of anti-glaucoma medications but are not associated with heterochromia iridis.
* **Option B:** Beta-blockers, such as timolol, are another class of anti-glaucoma medications that do not cause heterochromia iridis.
* **Option D:** Carbonic anhydrase inhibitors, such as acetazolamide, are a class of anti-glaucoma medications that do not cause heterochromia iridis.

**Clinical Pearl / High-Yield Fact**
It's essential to note that heterochromia iridis caused by epinephrine is usually reversible upon discontinuation of the medication.

**Correct Answer:** C. Epinephrine