Final answer:
To treat the high blood pressure and hypertensive retinopathy in a 56-year-old diabetic woman, a calcium channel blocker or oral diuretic would be suitable medication options to rapidly control her blood pressure.
Step-by-step explanation:
The treatment of a 56-year-old woman with diabetes, presenting with loss of vision, blurring, and features of hypertensive retinopathy with a blood pressure of 210/100 mmHg, would require urgent medical management. Considering that her blood pressure is significantly high, a combination of antihypertensive medications may be necessary to achieve rapid and effective blood pressure control. A calcium channel blocker or an oral diuretic could be appropriate choices in this situation, as they have been shown to be effective in lowering blood pressure quickly. These medications will also help prevent the progression of hypertensive retinopathy and other complications related to hypertension and diabetes.