The correct option is D A - IV, B - III, C - I, D-II
Blood is the circulatory body fluid. It is composed of plasma, red blood cells, white blood cells and the platelets. The plasma, which is a viscous straw-coloured fluid, is composed of water, proteins, minerals, etc. Some of the major proteins found in the blood plasma are globulins, albumins and fibrinogen. Fibrinogen helps in the process of coagulation of blood. The inactive fibrinogen is converted to its active form (fibrin) with the help of the enzyme, thrombin. Fibrins help in the formation of a clot or a coagulam at the site of a cut or an injury, thereby, helping in the clotting of the blood. Globulin helps in providing immunity by participating in various defense mechanisms of the body. The osmotic balance is maintained with the help of the protein, albumin. Serum is the plasma excluding the clotting factors.