## Core Concept
The daily protein requirement for children varies based on their age, weight, and activity level. Protein is essential for growth and development, particularly in children. The recommended dietary allowance (RDA) for protein is expressed in grams per kilogram of body weight per day.

## Why the Correct Answer is Right
The recommended protein intake for a 2-year-old child is approximately 1.6 grams per kilogram of body weight per day. This requirement supports growth, maintenance, and repair of body tissues. For a typical 2-year-old child weighing around 12 kilograms, the daily protein requirement would be about 19 grams (1.6 grams/kg/day * 12 kg).

## Why Each Wrong Option is Incorrect
**Option A:** 10 grams - This is lower than the recommended daily intake for a 2-year-old child, considering their growth needs.
**Option B:** 15 grams - While closer, it still does not meet the recommended requirement of 1.6 grams/kg/day for a child of this age.
**Option D:** 25 grams - Although not drastically higher than the correct answer, it exceeds the basic requirement for a child of this age group without considering specific individual needs.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the protein requirement for children is based on their weight. The general recommendation is about 1.6 grams/kg/day for toddlers. This fact can help in estimating nutritional needs across different age groups and weights.

## Correct Answer Line
**Correct Answer: C. 20 grams.**