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: Pathology
Swollen joint, anemic, loose teeth & dentin dysplasia are
because of deficiency of: 
Select and explain. 
A. Vitamin C, B. Vitamin D, C. Vitamin B1, D. Vitamin E & D
A: Vitamin C
Answer: A: Vitamin C 
Explanation: None