This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urinary tract, Subject name: Pathology
The cause of oedema in nephritic syndrome 
Select and explain. 
A. Increase in plasma protein concentratn, B. Decrease plasma protein concentratn, C. Reduced plasma osmotic pressure, D. Sodium and water retention
D: Sodium and water retention
Answer: D: Sodium and water retention 
Explanation: Robbins page no p922 Glomerular diseases presenting with a nephritic syn- drome are often characterized by inflammation in the glomeruli. The nephritic patient usually presents with hematuria, red cell casts in the urine, azotemia, oliguria, and mild to moderate hypeension. Proteinuria and edema are common, but these are not as severe as those encountered in the nephrotic syndrome, discussed later. The acute nephritic syndrome may occur in such multi- system diseases as SLE and microscopic polyangiitis.