This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Layers of epidermis, dermis, Subject name: Dental
Normal turnover rate of epidermis: 
Select and explain. 
A. 2 weeks, B. 4 weeks, C. 6 weeks, D. 8 weeks
D: 8 weeks
Answer: D: 8 weeks 
Explanation: Epidermal turnover time - skin doubling time -Time taken by keratinocytes to move from Stratum Basale to environment. -Around 14 days are required to move from Stratum Basale to reach lowermost layer of Stratum Corneum & 14 days to cross Stratum Corneum. -Sloughing off requires 28 days So total ETT =56 days (8 weeks) The turnover time in psoriasis = 4 days.