Final answer:
The clear part of blood containing clotting agents is plasma. Plasma is a yellowish liquid that forms the liquid component of blood, and it contains substances such as water, coagulation factors, and antibodies. Serum, by contrast, is the portion of plasma without clotting factors.
Step-by-step explanation:
The clear part of whole blood that contains clotting agents is plasma (option a.). Blood plasma is a yellowish liquid that makes up about half of the total blood volume. It consists of 90 percent water along with various substances, including blood coagulation factors, serum, antibodies, hormones, nutrients, and waste products. Serum is the component of plasma that remains after clotting has occurred, which means it does not contain clotting factors. Therefore, serum does not have the ability to clot on its own. The primary function of plasma is to transport cells and a variety of substances throughout the body, whereas serum acts as a carrier for electrolytes, antibodies, antigens, hormones, and any exogenous substances such as drugs and microorganisms.