Work Step by Step
Option A is incorrect. Plasma is a light yellow liquid in blood that contains mainly water and a little bit of dissolved substances such as cholesterol, enzymes, hormones, and wastes. Option C is incorrect. Phagocytes are white blood cells that may travel in the blood. Option D is incorrect. Platelets are cell fragments that play an important role in blood clotting. Option B is correct. Blood does not contain mucus, which is a slimy substance that has several uses in the body such as lubrication and protection. Mucus is made and secreted by mucus glands.