This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Scabies and other infestations, Subject name: Dental
[{'content': 'Disorder of hyperkeratinization? \nSelect and explain. \nA. Icthyosis vulgaris, B. Vitiligo, C. Atopic dermatitis, D. Seborrhic dermatitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hyperkeratinization: Icthyosis vulgaris Vitiligo is hypopigmentry disorder. Atopic dermatitis: itchy lichenified lesions over flexors of elbow and knee Seborrheic dermatitis: scaly lesion Icthyosis vulgaris: AD disorder Reduced or absence of filaggrin protein and granular layer Fish-like scales on the skin.', 'role': 'assistant'}]