**Core Concept**
Beta blockers are a class of medications that inhibit the effects of epinephrine (adrenaline) and norepinephrine on the heart, lungs, and other organs. In the context of ophthalmology, beta blockers are used to reduce intraocular pressure (IOP) in patients with glaucoma by decreasing the production of aqueous humor.

**Why the Correct Answer is Right**
The correct answer is a long-acting beta blocker that is specifically chosen for its prolonged duration of action to effectively manage IOP. This medication, **Timolol**, works by inhibiting the beta-1 and beta-2 adrenergic receptors in the ciliary body, thereby reducing the production of aqueous humor. Timolol's prolonged action is due to its lipophilic nature, which allows it to penetrate the cornea and exert its effects over an extended period.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a long-acting ocular beta blocker. While it may be a beta blocker, it does not have the necessary properties for prolonged action in the eye.
* **Option B:** This option is incorrect because it is a different class of medication altogether. It is not a beta blocker and therefore does not have the same mechanism of action.
* **Option D:** This option is incorrect because it is another type of medication that is not a beta blocker. It may have some similar effects, but it is not a long-acting ocular beta blocker.

**Clinical Pearl / High-Yield Fact**
When choosing an ocular beta blocker, it's essential to consider the duration of action and the specific indications for use. Long-acting beta blockers like Timolol are often preferred for managing chronic glaucoma, while shorter-acting agents may be used for acute angle-closure glaucoma.

**Correct Answer:** C. Timolol