This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
A 50 years old male presents with severe refractory hypeension, weakness, muscle cramps and hypokalemia, the most likely diagnosis is 
Select and explain. 
A. Hypoaldosteronism, B. Hyperaldosteronism, C. Cushing syndrome, D. Pheochromocytoma
A: Hypoaldosteronism
Answer: A: Hypoaldosteronism 
Explanation: Manifestation of Conn's Syndrome (Primary Hyperaldosteronism) Muscle weakness and fatigue (due to hypokalemia) Hypeension without edema Polyuria and polydipsia Investigations Hypokalemia * Metabolic alkalosis * Hypernatremia * Increased Aldosterone * Low renin