A 35-year-old man has slow-growing lymphadenopathy and B-symptoms. H&E micrographs and an S-100 immunostain of a lymph node are shown. 

What is your diagnosis and what is the most likely mutation.

A. Langerhans cell histiocytosis, MAP2K1

B. Rosai-Dorfman disease, BRAF V600E

C. Rosai-Dorfman disease, MAP2K1

D. Langerhans cell histiocytosis, BRAF V600E