This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification of carbohydrate, Subject name: Biochemistry
Glucuronic acid and Iduronic acid are: 
Select and explain. 
A. Anomers, B. Enantiomers, C. Functional isomers, D. Epimers
D: Epimers
Answer: D: Epimers 
Explanation: option d : Glucuronic acid and Iduronic acid are Epimers Epimers are stereoisomers that differ around the configuration of a single asymmetric carbon other than the anomeric carbon. Epimers of glucose can be remembered as MAGI. Mannose -C2 epimer, Allose -C3 epimer, Galactose -C4 epimer Idose -C5 epimer.