The primary role of aldosterone is?

Correct option is A

Sol. Aldosterone is a mineralocorticoid hormone secreted by the adrenal cortex that acts on the renal tubules. It increases sodium reabsorption and potassium excretion, helping regulate blood pressure and electrolyte balance. This effect conserves water in the body through sodium retention.
Explanation of each option:
· (a) Conserve sodium, promote potassium excretion – Correct. This is the main physiological action of aldosterone in the kidneys.
· (b) Conserve potassium, promote sodium excretion – Opposite to what aldosterone does; it would lead to fluid loss.
· (c) Conserve sodium and potassium – Incorrect, as aldosterone promotes potassium loss, not conservation.
· (d) Promote excretion of sodium and potassium – This would cause dehydration and electrolyte imbalance; aldosterone prevents this.