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
Glucose tolerance test is usually done to assess: 
Select and explain. 
A. Acute pancreatitis, B. Carcinoma of head of pancreas, C. Acinar function of the pancreas, D. Endocrine dysfunction of pancreas
D: Endocrine dysfunction of pancreas
Answer: D: Endocrine dysfunction of pancreas 
Explanation: None