What is contained in the fluid portion of the blood?

The fluid portion of the blood, known as plasma, contains a variety of substances that play vital roles in the body. One of the key components of plasma is proteins, which include albumin, globulins, and fibrinogen. These proteins are essential for maintaining osmotic pressure, immune function, and blood clotting. Additionally, hormones are dissolved in the plasma and are crucial for communication between different parts of the body, regulating processes such as growth, metabolism, and stress response.

While the fluid component of blood does contain nutrients and waste products, it is the presence of hormones and proteins that is particularly significant, as they are critical to the overall functioning of the body's systems. The other options either misrepresent the contents of plasma or limit its composition too narrowly.