This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
Which of the following is the synthetic vitamer of vitamin K? 
Select and explain. 
A. Phylloquinone, B. Menaquinone, C. Menadione, D. All of the above
C: Menadione
Answer: C: Menadione 
Explanation: Vitamers are different forms of vitamins. Vitamin K has three different vitamers as: