This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Not obtained from plant source ? 
Select and explain. 
A. Cobalamine, B. Riboflavin, C. Thiamine, D. Vitamin A
A: Cobalamine
Answer: A: Cobalamine 
Explanation: Ans. is 'a' i.e., CobalamineVitamin B12 (cobalamin or cynocobalmin) is present only in food of animal origin. Other three vitamins can be taken from plant source.