This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
Which of the following is a feature of primary adrenal coical failure ? 
Select and explain. 
A. Hypopigmentation, B. Sodium and water depletion, C. Hypeension, D. Hypokalemia
B: Sodium and water depletion
Answer: B: Sodium and water depletion 
Explanation: hyper pigmentation, hypotension and hyperkalemia . there is hyponatremia due to sodium lodmss in urine due to aldosterone deficiency ( Harrison 17 pg 2264)