This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Malnutrition, Subject name: Pediatrics
What is the most common underlying cause responsible for the disease in which this X ray finding is seen? 
Select and explain. 
A. Calcium deficiency, B. Phosphate deficiency, C. Vit D deficiency, D. Vit C deficiency
C: Vit D deficiency
Answer: C: Vit D deficiency 
Explanation: The given X rays shows widening, cupping & fraying at metaphyseal ends of forearm bones- suggestive of Rickets Vitamin C deficiency- Pencil thin coex, Pelken spurs, Wimberger ring sign