This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluids and Electrolyte Imbalance, Subject name: Medicine
Which of the following leads to hyponatremia and low osmolality: 
Select and explain. 
A. Hyperlipidemia, B. Hyperproteinemia, C. IVIG therapy, D. CHF
D: CHF
Answer: D: CHF 
Explanation: CHF is characterized by low perfusion of kidney stimulating R.A.A.S and resultant absorption of salt and dispropoionate amount of water would lead to hyponatremia with decreased osmolality Isotonic hyponatremia is seen with hyperlipidemia and hyperproteinemia like in paraproteinemia IV immunoglobulin therapy also interferes with measurement of serum sodium leading to pseudo-hyponatremia