## **Core Concept**
The daily maintenance fluid requirement for children can be calculated using the **Holliday-Segar formula**. This formula estimates the basal fluid needs for children based on their body weight.

## **Why the Correct Answer is Right**
The Holliday-Segar formula is as follows:
- For the first 10 kg of body weight, the fluid requirement is **100 mL/kg/day**.
- For the next 10 kg (11-20 kg), it is **50 mL/kg/day**.
- For each kilogram above 20 kg, it is **20 mL/kg/day**.

For a child weighing 10 kg, the daily maintenance fluid requirement would be **100 mL/kg/day * 10 kg = 1000 mL/day**.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Without a specific value, it's hard to directly refute, but if it's not 1000 mL, it's incorrect based on the Holliday-Segar formula.
- **Option B:** Similarly, without a value, assume it's incorrect if not aligned with 1000 mL for a 10 kg child.
- **Option D:** This would be incorrect because it does not align with the 1000 mL calculation for a 10 kg child based on the Holliday-Segar formula.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is the **4-2-1 rule** as an alternative way to recall the Holliday-Segar formula: for every 4 kg, 2 kg, and 1 kg (respectively for the weight ranges), the fluid requirements are approximately 100 mL/kg/day, 50 mL/kg/day, and 20 mL/kg/day. This helps in quick estimation during exams.

## **Correct Answer Line**
**Correct Answer: C. 1000 mL.**