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: Medicine
A 2-year-old child comes with discharge, seborrheic dermatitis, polyuria and hepatosplenomegaly. Which of the following is the most likely diagnosis - 
Select and explain. 
A. Leukemia, B. Lymphoma, C. Langerhan's cell histiocytosis, D. Germ cell tumour
C: Langerhan's cell histiocytosis
Answer: C: Langerhan's cell histiocytosis 
Explanation: None