The correct option is (a) Proximal tubule
Explanation: Osmotic diuretics work in the proximal tubule, producing an osmotic effect. It pulls water into the blood vessels and nephrons from the surrounding tissues. Osmotic diuretics reduces cellular edema, increased urine production, causing diuresis. Rapid excretion of water, sodium, and other electrolytes, as well as excretion of toxic substances from the kidney. Reduced excessive intraocular pressure.