## Core Concept
The calorie requirement for a child can be estimated based on their weight, taking into account their age and activity level. For children, the estimated calorie needs are often provided in terms of calories per kilogram of body weight per day.

## Why the Correct Answer is Right
The estimated calorie requirement for a child weighing 15 kg is approximately 100 kcal/kg for the first 10 kg, 50 kcal/kg for the next 10 kg (from 11-20 kg), and 10-20 kcal/kg for each kilogram above 20 kg. For a 15 kg child, the calculation would be: (10 kg * 100 kcal/kg) + (5 kg * 50 kcal/kg) = 1000 + 250 = 1250 kcal/day. This matches option .

## Why Each Wrong Option is Incorrect
- **Option A:** This option suggests a calorie requirement that is too low for a child weighing 15 kg, not aligning with standard nutritional guidelines.
- **Option B:** This option is higher than the calculated requirement and does not accurately reflect the estimated calorie needs for a child of this weight.
- **Option D:** This option is also not in line with the estimated calorie requirements for a child weighing 15 kg, being either too high or too low compared to standard guidelines.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the calorie needs of children are generally estimated as follows: 100 kcal/kg/day for the first 10 kg of body weight, 50 kcal/kg/day for the next 10 kg (11-20 kg), and 20 kcal/kg/day for the weight above 20 kg. This formula provides a quick estimation of daily calorie needs for children.

**Correct Answer: .**