This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Maximum contribution of plasma osmolarity is by 
Select and explain. 
A. Urea, B. Glucose, C. Sodium, D. Albumin
C: Sodium
Answer: C: Sodium 
Explanation: Sodium is the major contributor plasma osmolarity Ref: guyton and hall textbook of medical physiology 12 edition page number: 50,51,52