Concept:Vitamin K is essential for the synthesis of blood clotting factors in the liver.Explanation:When a blood vessel is injured, the body forms a clot to stop bleeding.This process requires clotting factors, which are proteins activated with the help of vitamin K.If vitamin K is deficient, these clotting factors become inactive.As a result, blood cannot clot properly, leading to excessive bleeding even from a minor injury.Answer:A. K