Mark the pair of substances among the following which is essential for coagulation of blood.

Options

A. Heparin and calcium ions
B. Calcium ions and platelet factors
C. Oxalates and citrates
D. Platelet factors and heparin

Answer

B

Explanation

Calcium plays an important role in blood clotting. During coagulation thromboplastin (factor III) is released by the damage tissues reaction with prothrombin (II) which together with calcium (IV) forms thrombin which converts fibrinogen into fibrin (I).