You are answering a USMLE-style medical question. Question: A 52-year-old man comes to the physician for an annual physical examination. He reports that his vision has progressively improved over the past 6 months and he no longer needs the glasses he used while driving. He has hypertension and type 2 diabetes mellitus. Current medications include glyburide, hydrochlorothiazide, and enalapril. Examination shows 20/20 vision bilaterally. Fundoscopy shows a few microaneurysms of retinal vessels. Which of the following is the most likely explanation for this patient's improved vision? Options: A) Denaturation of lens protein B) Liquefication of the vitreous body C) Increased ciliary muscle tone D) Increased lens elasticity Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.