This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune skin disorders, Subject name: Dental
Oil drop is seen in 
Select and explain. 
A. Psoriasis of nails, B. Clubbing, C. Lichen planus of nails, D. Tinea unguium
A: Psoriasis of nails
Answer: A: Psoriasis of nails 
Explanation: Oil drop sign is seen in nail psoriasis IADVL textbook of dermatology page 1035