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
Basal cell degeneration seen in - 
Select and explain. 
A. Lichen Planus, B. Psoriasis, C. pemphigus, D. Pemphigoid
A: Lichen Planus
Answer: A: Lichen Planus 
Explanation: Lichen planus is an inflammatory T cell mediated autoimmune disorder affecting skin, hair, nails and mucous membranes. Lichen planus triggers T cell mediated autoimmune damage to basal keratinocytes that manifest as altered self antigens on their surface. Ref Harrison20th edition pg 1256