This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
Which of the following is not a test for amino acids? 
Select and explain. 
A. Biuret test, B. Xanthoproteic reaction, C. Ninhydrin test, D. Molisch's test
D: Molisch's test
Answer: D: Molisch's test 
Explanation: Biuret test, ninhydrin test, and xanthoproteic test are tests of proteins. Molisch test is that for carbohydrates.Ref: Textbook of medical biochemistry, MN Chatterji, 8th edition, page no: 80