This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Anatomy
[{'content': 'Most common Non Hodgkins lymphoma of orbit: \nSelect and explain. \nA. B cell, B. T cell, C. NK cell, D. Plasma cell', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Non Hodgkins lymphoma of the B cell lineage is the most common type in the orbit ..Eyelid ,conjuctival,and orbit tumors. The most frequently encountered primary neoplasms of the orbit are vascular in origin like the capillary hemangioma, the lymphangioma and the encapsulated cavernous hemangioma Mc intaocular tumour in children:Retinoblastoma Mc intraocular tumour in adults: choroidal malignant melanoma. (ref Robbins 8/e p1348, eyelid,conjuctival, and orbital tumour 2/e p746)', 'role': 'assistant'}]