## Core Concept
The water content in the human body varies across different age groups. Infants have a higher percentage of body water compared to adults. This is due to the differences in body composition, such as a higher proportion of lean body mass and a lower amount of body fat.

## Why the Correct Answer is Right
Infants have a higher water content, approximately 70-80% of their body weight, due to their higher lean body mass and lower fat content. This percentage decreases as the child grows and develops, eventually reaching about 55-60% in adults. The high water content in infants is crucial for their growth and development.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not accurately represent the high water content found in infants.
- **Option B:** This option is incorrect because it suggests a lower water content than what is typically found in infants.
- **Option D:** This option is incorrect because it represents a water content more typical of adults rather than infants.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the higher water content in infants makes them more susceptible to dehydration. Therefore, it's crucial to carefully manage fluid balance in pediatric patients. A common mnemonic to help remember the approximate water content in different age groups is that infants have about 70-80% water content, children have about 60-70%, and adults have about 55-60%.

**Correct Answer: C. 70-80%**