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: Surgery
The disadvantage of elemental include diets in childrena) Hypertonic dehydrationb) Lower caloric inputc) Dumping syndromed) High nitrogen input 
Select and explain. 
A. ad, B. bc, C. ac, D. bd
C: ac
Answer: C: ac 
Explanation: None