This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of skin, Subject name: Dental
[{'content': 'Acanthosis involves- \nSelect and explain. \nA. Str spinosum, B. Str granuolosum, C. Str Basale, D. Str Corneum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Acanthosis is diffuse epidermal hyperplasia (thickening of the skin). It implies increased thickness of the Malpighian layer (stratum basale and stratum spinosum). Acanthosis nigricans is often associated with type 2 diabetes, and is usually observed in the back of neck, axilla, and other folded regions of the skin. Ref Harrison20th edition pg 1206', 'role': 'assistant'}]