This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Dermatitis, Subject name: Dental
[{'content': 'Dermatitis and alopecia may occur due to deficiency of \nSelect and explain. \nA. Magnesium, B. Zinc, C. Calcium, D. Molybdenum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: zinc is a trace element necessary for maintaining healthy skin , healing of wounds, growth,fetaal development and brain functions zinc deficiency acrodermatitis enteropathica- dermatitis around orifices, nonscarring alopecia, glossitis, diarrhoea.growth retardation. Ref Harrison20th edition pg 1345', 'role': 'assistant'}]