Which of the following vitamin is helpful in the blood clotting?

Vitamin helpful in the blood clotting is Vitamin $K$.

Vitamin K is a fat soluble vitamin required for normal blood clotting. Its deficiency leads to slow or delayed blood clotting and haemorrhage (blood loss). Vitamin K is required for synthesis of prothrombin in the liver where the vitamin K-dependent carboxylation in prothrombin synthesis occurs.

Note: Question has been slightly modified for its correctness.