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: Gynaecology & Obstetrics
Neonatal alloimmune thrombocytopenia is caused by 
Select and explain. 
A. B19 parvovirus  infection, B. Maternal - fetal platelet antigen disparity, C. CMV infection, D. Sepsis
B: Maternal - fetal platelet antigen disparity
Answer: B: Maternal - fetal platelet antigen disparity 
Explanation: Alloimmune thrombocytopenia is caused by maternal fetal platelet antigen disparity.