Which prescribed medication should the nurse give first to a patient who has just been admitted to a hospital with acute angle-closure glaucoma?

Rationale: A. Acetazolamide, a carbonic anhydrase inhibitor, decreases aqueous humor production, but oral administration acts more slowly and is not the priority in acute angle-closure glaucoma. B. Mannitol, an osmotic diuretic, is given intravenously to rapidly decrease intraocular pressure by drawing fluid from the eye into the bloodstream. This is the priority medication to prevent permanent vision loss. C. Betaxolol, a beta-blocker, helps reduce intraocular pressure but acts more slowly than IV mannitol and is not the first-line emergency intervention. D. Morphine may help with pain but does not address the dangerously elevated intraocular pressure that threatens vision in acute angle-closure glaucoma.