This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which of the following has no Tm value ? 
Select and explain. 
A. Albumin, arginine, B. Betahydroxybutyrate, glucose, C. Glucose haemoglobin, phosphate, D. Urea
D: Urea
Answer: D: Urea 
Explanation: D i.e. Urea