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: Skin
Dermatitis and alopecia are due to deficiency of: 
Select and explain. 
A. Zinc, B. Molybodenum, C. Magnesium, D. Calcium
A: Zinc
Answer: A: Zinc 
Explanation: A i.e. Zinc