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
Glanzmann thrombasthenia is due to deficiency of 
Select and explain. 
A. GP IIb - IIIa, B. GP 1b - Ix, C. Von willebrand factor IA, D. Von willebrand factor 2B
B: GP 1b - Ix
Answer: B: GP 1b - Ix 
Explanation: None