This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'IgE receptors are present on \nSelect and explain. \nA. Mast cells, B. NK cells, C. B cells, D. Histiocytes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref Robbins 9/e p201 Type 1 hypersensitivity is a rapid immunological reaction occuring in a previously sensitized individual that is triggered by the binding of an antigen to IgE antibody on the surface of mast cells', 'role': 'assistant'}]