Vitamin k is synthesized by bacteria in the mouth pancreas large intestine stomach.

The correct answer is- Large intestine

Explanation:

Vitamin K is an very essential vitamin that is required by the body to produce many clotting factors for example clotting factor II, IX, X, etc.  

Green vegetables are the primary source of providing vitamin K1(phylloquinone) and vitamin K2(menaquinones) is synthesized in the body by some bacteria which is present in the large intestine.  

Bacteria such as E.coli are capable of synthesizing vitamin K2 in large intestine from where it is absorbed in lymph present in the intestine. So the correct answer is the large intestine.