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: Pathology
[{'content': 'The type of lymphocyte which is predominent in chronic lymphatic leukemia - \nSelect and explain. \nA. T lymphocyte, B. B lymphocyte, C. K cells, D. Helper T lymphocyte', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]