This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
Normal plasma osmolality in mOsmol/kg H2O 
Select and explain. 
A. 290, B. 385, C. 485, D. 585
A: 290
Answer: A: 290 
Explanation: The osmolarity is the number of osmoles per litre of solution The freezing point of normal human plasma averages -0.54 degC, which corresponds to an osmolal concentration in plasma of 290 mOsm/L Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:6