**Core Concept**
The recommended daily water intake varies based on factors like age, sex, climate, and physical activity level. The per capita allowance of water per day is a guideline that helps maintain proper hydration and overall health.

**Why the Correct Answer is Right**
The World Health Organization (WHO) recommends a minimum of 2 liters (67.6 ounces) of water per day for adults in a temperate climate with a moderate level of physical activity. This recommendation is based on the average water loss through urine, sweat, and feces. The human body is composed of approximately 60% water, and adequate hydration is essential for maintaining proper bodily functions, such as regulating body temperature, transporting nutrients and oxygen to cells, and removing waste products.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the recommended daily water intake can vary depending on individual factors, and a fixed amount like 1 liter may not be sufficient for everyone.
* **Option B:** This option is incorrect because the recommended daily water intake is not solely based on body weight, but also on other factors like physical activity level, climate, and age.
* **Option C:** This option is incorrect because the recommended daily water intake is not solely based on the amount of water consumed through food, but also on the amount of water lost through urine, sweat, and feces.

**Clinical Pearl / High-Yield Fact**
It's essential to note that individual water needs may vary, and some people may require more or less water depending on their specific circumstances. For example, athletes or individuals living in hot and humid climates may require more water to stay hydrated.

**Correct Answer:** C. 2 liters.