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
The drug used in heparin overdose is: 
Select and explain. 
A. Protamine sulfate, B. Phylloquinone, C. Ticlopidine, D. Clopidogrel
A: Protamine sulfate
Answer: A: Protamine sulfate 
Explanation: Protamine sulfate is an antidote of heparin overdose whereas vitamin K is used as an antidote for warfarin toxicity.