This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Kidney Disease & Diabetic Nephropathy, Subject name: Medicine
Central nervous system manifestations in chronic renal failure are a result of all of the following except: 
Select and explain. 
A. Hyperosmolarity, B. Hypocalcemia, C. Acidosis, D. Hyponatremia
B: Hypocalcemia
Answer: B: Hypocalcemia 
Explanation: OPTION B- Hypocalcemia in CKD is linked to development secondary hyperparathyroidism The concomitant hyperphosphatemia leads to calcification of vessels which explains worsening atherosclerosis. Hypocalcemia in CKD patients leads to endocrinological cardiovascular complications. OPTION A- Hyperosmolarity occurs as urea is one of the parameters deciding serum osmolality.Sodium, potassium, glucose , urea determine plasma osmolality. OPTION C- Acidosis will damage Blood brain barrier and will cause uraemic encephalopathy OPTION D- Hyponatremia secondary to volume overload explains seizures in these patients.