## **Core Concept**
The question tests knowledge on the impact of severe infectious enteritis on intestinal enzyme activity, particularly in children. Infectious enteritis can lead to damage of the intestinal mucosa, affecting the production of various enzymes crucial for digestion and absorption. One key enzyme that can be impacted is lactase.

## **Why the Correct Answer is Right**
Lactase is an enzyme produced in the small intestine that breaks down lactose, a sugar found in milk and other dairy products, into glucose and galactose for absorption. Severe infectious enteritis can cause damage to the intestinal mucosa, leading to a decrease or temporary absence of lactase production. This condition is known as secondary or acquired lactose intolerance. It is a well-documented consequence of intestinal infections, especially in children, as their gut is still developing.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Not provided, assuming it's an incorrect enzyme.
- **Option B:** Not provided, assuming it's another incorrect enzyme.
- **Option C:** This seems to be a placeholder for the correct answer, which we identified as lactase.
- **Option D:** Not provided, assuming it's an incorrect enzyme.

Given that specific details about options A, B, and D are not provided, we focus on the understanding that lactase deficiency is a known complication of severe infectious enteritis.

## **Clinical Pearl / High-Yield Fact**
A significant clinical pearl is that secondary lactose intolerance due to infectious enteritis is usually temporary. The condition often resolves once the intestinal mucosa heals, which can take several weeks. During this time, lactose-containing products may need to be avoided or lactase enzyme supplements may be recommended to manage symptoms.

## **Correct Answer: C. Lactase**