Which of the following is NOT considered a component of blood?

The choice indicating skin cells is not considered a component of blood is accurate because blood is a specific bodily fluid that consists of various cellular and non-cellular elements, but skin cells do not belong to this category. Blood primarily comprises red blood cells, white blood cells, platelets, and plasma, which all have key roles in transporting oxygen, fighting infections, and aiding in clotting, respectively. Skin cells belong to the integumentary system and are responsible for forming the outer barrier of the body, which serves entirely different functions in terms of protection and regulating body temperature. Thus, skin cells do not contribute to the composition or function of blood, establishing this choice as the correct answer.