Which mineral is essential for blood clotting?

The vitamin, which is essential for blood clotting is

Assertion : The process of clotting can occur in absence of all cellular elements except platelets Reason : Vitamin K is essential for blood clotting.

Assertion. Prothrombin is essential for blood clotting . Reason Prothrombin is synthesized in the liver in the presence of Ca^(++) .

The first event in blood clotting is

Vitamin necessary for blood clotting is :