Read the following paragraph regarding the blood coagulation cascade and identify the correct option for the blanks A, B, C, and D. An injury stimulates the formation of an enzyme complex [A]. This complex [A] is required to convert an inactive protein [B] into [C]. [C] in turn converts [D] into fibrins to form the clot.

Step-by-step solution

The coagulation of blood involves a cascade of enzymatic reactions. An injury or trauma stimulates the formation of an enzyme complex called thrombokinase [A]. Thrombokinase is required to convert an inactive protein present in the plasma called prothrombin [B] into its active form, thrombin [C]. Thrombin [C] then acts as an enzyme to convert inactive fibrinogen [D] into fibrins, which form the network of the clot. Therefore, A is Thrombokinase, B is Prothrombin, C is Thrombin, and D is Fibrinogen. Answer: A - Thro