Blood is approximately what percentage water?

Blood is composed of approximately 90% water, which allows it to effectively transport nutrients, hormones, and waste products throughout the body. This high water content is essential for maintaining blood volume and viscosity, ensuring that oxygen and other vital substances can be efficiently circulated. Oxygen and carbon dioxide, for example, dissolve in the plasma, which is primarily made of water, facilitating gas exchange in the lungs and tissues.

While option D suggests that blood is about 80% water, which is not entirely accurate, it is closer than the other options. The other percentages incorrectly suggest lower water content, undermining the critical role water plays in the composition and function of blood. Understanding the water content of blood is key in fields like medicine and biology, as it informs health assessments and hydration needs.