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: Medicine
Long term assessment of glucose control can be made by: 
Select and explain. 
A. Estimation of post prandial blood sugar, B. Estimation of fasting blood sugar, C. Estimation of urine sugar level, D. Estimation of blood level of glycosylated hemoglobin
D: Estimation of blood level of glycosylated hemoglobin
Answer: D: Estimation of blood level of glycosylated hemoglobin 
Explanation: None