Which of the following statements are true of chemical blood clotting? (Read carefully and select all of the correct statements.)

A)Many of the clotting factors are produced by the liver, but some are produced by the spleen.
B)Fibrinogen is changed to fibrin in stage 1 of clotting.
C)Calcium ions are needed for all three stages of clotting.
D)Prothrombin activator changes thrombin to prothrombin.
E)The actual clot is made of fibrin.
F)The purpose of clot retraction is to create a smaller area to be repaired.
G)The purpose of fibrinolysis is to strengthen a newly formed clot.
H)The endothelium of blood vessels is smooth and helps prevent abnormal clotting.