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: Pharmacology
Heparin induced thrombocytopenia is due to antibodies against 
Select and explain. 
A. PF - 1, B. PF - 2, C. PF - 3, D. PF - 4
D: PF - 4
Answer: D: PF - 4 
Explanation: Antibodies against platelet factor-4 (PF-4) causes aggregation of platelets and thrombosis, thus leads to thrombocytopenia.