**Core Concept**
Ketotifen is a medication that possesses both antihistaminic and anti-allergic properties. It is an inverse agonist of the H1 receptor and also has anti-inflammatory effects through the inhibition of the release of histamine and other mediators from mast cells.

**Why the Correct Answer is Right**
Ketotifen works by binding to the H1 receptor, thereby reducing the histamine-mediated allergic response. This results in decreased symptoms such as itching, sneezing, and runny nose. Additionally, ketotifen inhibits the release of histamine from mast cells, further reducing the allergic response. This dual action makes ketotifen a useful medication for the treatment of allergic conditions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because ketotifen is not an anticholinergic medication, which would block the action of acetylcholine at muscarinic receptors.
**Option B:** This option is incorrect because ketotifen does not have significant antifungal properties, unlike some other medications.
**Option C:** This option is incorrect because ketotifen is not a beta-blocker, which would affect the sympathetic nervous system and heart rate.

**Clinical Pearl / High-Yield Fact**
Ketotifen is also used in some countries as a treatment for ocular allergies, such as conjunctivitis and keratitis. Its anti-inflammatory effects make it a useful medication for these conditions.

**Correct Answer: C. Antihistaminic - anti-allergic agent.**