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: Pediatrics
One of the intestinal enzymes that are generally deficient in children following an attack of severe infectious enteritis is – 
Select and explain. 
A. Lactase, B. Trypsin, C. Lipase, D. Amylase
A: Lactase
Answer: A: Lactase 
Explanation: `Because Lactase activity in the mucosa is at best marginal, this enzyme is particularly likely to be depleted secondary to diffuse mucosal disease' - Nelson
Causes of Acquired Lactase deficiency
1. Acute Infective enteritis

Viral gastroenteritis   
Bacterial gastroenteritis       

2. Cystic fibrosis                                
3. Protein-energy malnutrition    
4. Cow's milk protein intolerance  
5. Prolonged use of drugs like Neomycin.