What are the main components of blood?

The main components of blood include plasma, red blood cells, and platelets, making this the most comprehensive answer.

Plasma is the liquid portion of blood, comprising about 55% of its total volume. It is mostly water and contains proteins, electrolytes, hormones, nutrients, and waste products, serving as a medium for transporting these substances throughout the body.

Red blood cells (erythrocytes) are essential for transporting oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. They play a critical role in maintaining the oxygenation of the body's organs and systems.

Platelets (thrombocytes) are important for blood clotting. They gather at sites of blood vessel injury, helping to form clots to prevent excessive bleeding.

The combination of these three components is integral to the proper functioning of the circulatory system and overall homeostasis in the body.

While other options may include various components of blood, they do not encompass the full and essential triad of plasma, red blood cells, and platelets, which together are paramount for the transportation, regulation, and protection functions of blood.