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: Pathology
Acanthosis nigricans can occur due to - 
Select and explain. 
A. Increased multiplication of basal cells, B. Cornification of basal cells, C. Keratinisation of epidermal cells, D. All
C: Keratinisation of epidermal cells
Answer: C: Keratinisation of epidermal cells 
Explanation: Hyperplasia of stratum spinosum of the epidermis.
Hyperkeratosis → Thickening of Stratum corneum of epidermis (Cornification of epidermis).
Slight basal cell hyperpigmentation.