You are answering a USMLE-style medical question. Question: A researcher is studying risk factors for open-angle glaucoma in a group of elderly patients at a primary care clinic. He is curious if patients with diabetes (defined as fasting serum glucose ≥126 mg/dL on two separate readings) are at increased risk of developing open-angle glaucoma over time. Which of the following is the best statement of the null hypothesis for this study? Options: A) The future risk of open-angle glaucoma is the same in patients with and those without diabetes B) Having diabetes will not cause changes in risk of future open-angle glaucoma C) Diabetes is not associated with an increased prevalence of open-angle glaucoma D) Improved adherence to antidiabetics will not be effective in decreasing future open-angle glaucoma risk Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.