Which of the following is NOT a function of blood?

The function of blood primarily involves crucial roles such as transporting oxygen, providing nutrients, and regulating body temperature. Blood carries oxygen from the lungs to tissues and organs, ensuring that cellular respiration can occur. It also transports nutrients absorbed from the digestive system to all cells of the body, supporting metabolism and energy production.

In addition to these roles, blood plays a vital part in maintaining homeostasis, which includes regulating body temperature through mechanisms such as vasodilation and vasoconstriction. By altering blood flow to the surface of the skin, the body can release or conserve heat as needed.

Producing hormones, while an essential process for bodily function, is not a direct role of blood itself. Hormones are produced by glands in the endocrine system and then transported throughout the body via the bloodstream. This distinguishes hormone production from the critical functions blood performs. Therefore, selecting that producing hormones is not a direct function of blood is accurate in the context of this question.