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
Dendritic cells located among keratinocytes at all suprabasal levels and belonging to reticuloendothelial system derived from bone marrow are 
Select and explain. 
A. Melanocytes, B. Langerhans cells, C. Lymphocytes, D. Merkel cell
B: Langerhans cells
Answer: B: Langerhans cells 
Explanation: None