This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Which of the following is the diagnostic test for pancreatic insufficiency? 
Select and explain. 
A. Schilling test, B. Serum lipase, C. Serum amylase, D. Faecal fat estimation
D: Faecal fat estimation
Answer: D: Faecal fat estimation 
Explanation: The gold standard test is an estimation of fecal fat. Serum amylase and lipase are elevated during acute attacks. Schilling test is done for cobalamine malabsorption.Ref: Harrison; 19th edition; Page no: 1938