Which of the following is essential for body functioning and found in every cell?

Water is essential for body functioning and is found in every cell. Its role in the body is critical for numerous physiological processes. Water serves as a solvent for biochemical reactions, transports nutrients and waste, regulates body temperature, and maintains cellular structure by providing turgidity to cells.

Every cell in the body requires water to remain hydrated and to perform its functions effectively. Without adequate water, cells can become dehydrated, leading to impaired cellular function and, ultimately, negative effects on overall health.

While fats, proteins, and vitamins play important roles in various bodily functions, they are not present in every cell in the same way that water is. Fats and proteins are vital for energy storage, structure, and function, while vitamins are necessary for a variety of metabolic processes but are not universally found in every cell. Water's unique role and presence in every cell underscores its critical importance for life and cellular activity.