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: Dental
A child presents with perioral rash and pigmentation of palmar area. What is the cause? 
Select and explain. 
A. Selenium deficiency, B. Manganese deficiency, C. Copper deficiency, D. Zinc deficiency
D: Zinc deficiency
Answer: D: Zinc deficiency 
Explanation: Option A: Selenium deficiency shows cardiomyopathy.
Option B: Manganese deficiency presents with hypercholesterolemia and weight loss.
Option C: Copper deficiency leads to neurological manifestations.