Which lifestyle modification should be prioritized for long-term management of a patient with hypertension?

Hypertension is driven by increased systemic vascular resistance, endothelial dysfunction, and dysregulation of the renin-angiotensin-aldosterone system, leading to sustained elevation of arterial pressure and long-term risk of cardiovascular, renal, and cerebrovascular complications. Rationale: A. Reducing dietary sodium decreases extracellular fluid volume and lowers blood pressure load, while increasing potassium-rich foods enhances natriuresis and promotes vasodilation through smooth muscle relaxation. This combination directly targets the pathophysiology of hypertension and is a cornerstone of long-term management. B. Excessive fluid intake (4 liters daily) may increase intravascular volume and worsen blood pressure in susceptible individuals. Fluid intake should be individualized rather than universally increased in hypertension management. C. A high-protein, low-carbohydrate diet does not directly address vascular resistance or sodium balance. While diet composition may influence weight, this approach is not evidence-based as a primary antihypertensive strategy. D. Avoiding dairy products is unnecessary and may reduce intake of beneficial nutrients such as calcium and potassium. Dairy consumption, especially low-fat options, can be part of a balanced diet supportive of blood pressure control.