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: Dental
Nikolsky sign not present in -a) Pemphigusb) Pemphigoidc) Vitiligod) Staphylococcal scalded syndrome 
Select and explain. 
A. cd, B. bc, C. bd, D. ac
B: bc
Answer: B: bc 
Explanation: None