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
[{'content': "Deficiency of the 'intrinsic factor of Castle' causes: \nSelect and explain. \nA. Microcytic anemia, B. Pernicious anemia, C. Cooley's anemia, D. Aplastic anemia", 'role': 'user'}, {'content': "Answer: B \nExplanation: Answer is B (Pernicious Anemia) Deficiency of Intrinsic factor leads to a specific form of vitamin B12 deficiency megaloblastic anemia called `Pernicious Anemia'. Pernicious Anemia also known as Addison's Anemia is a megaloblastic anemia due to deficiency of intrinsic factor (secreted by parietal cells of gastric mucosa) that is essential for vitamic B12 absorption. Note: 'Intrinsic factor' was first described by castle & coworkers and hence intrinsic factor is also called Intrinsic factor of Castle.", 'role': 'assistant'}]