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: Social & Preventive Medicine
A strict vegetarian, Raj Gopal - 23 years old foreign student in WMC is having lethargy, easy fatigue and palpitations. He is found to have macrocytic anemia on blood CP. He is suffering from deficiency of vitamin 
Select and explain. 
A. A, B. B1, C. D, D. B6
C: D
Answer: C: D 
Explanation: None