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': 'Glanzmann thrombasthenia is due to deficiency of \nSelect and explain. \nA. GP IIb - IIIa, B. GP 1b - Ix, C. Von willebrand factor IA, D. Von willebrand factor 2B', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]