**Core Concept**
The distribution of water in the human body is crucial for maintaining proper bodily functions, and it is essential to understand the proportion of water present in different compartments, including intracellular water. Intracellular water represents the water present within cells, which is vital for various cellular processes.

**Why the Correct Answer is Right**
Intracellular water accounts for approximately 40-50% of the total body water in a healthy individual. This is because cells contain a high proportion of water, which is necessary for maintaining cellular structure and function. The remaining 50-60% of body water is distributed in the extracellular space, including the interstitial fluid and plasma. The intracellular water content is higher in lean body mass, as it is closely related to the cell membrane's surface area and the cell's metabolic activity.

**Why Each Wrong Option is Incorrect**
* **Option A:** This range is too high to represent intracellular water, as it approaches the total body water content.
* **Option B:** This range is too low to represent intracellular water, as it is closer to the extracellular fluid volume.
* **Option C:** This range is closer to the extracellular fluid volume, which is not representative of intracellular water.

**Clinical Pearl / High-Yield Fact**
In a healthy adult, approximately 40-50% of total body water is found in the intracellular compartment, while 20-30% is found in plasma and 30-40% in interstitial fluid. Understanding the distribution of water in the body is essential for diagnosing and managing various clinical conditions, such as dehydration and edema.

**Correct Answer:** C. 40-50%.