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: Physiology
[{'content': 'Plasma thromboplastin antecedent is: \nSelect and explain. \nA. Anti hemophilic — A factor, B. Anti hemophilic — B factor, C. Anti hemophilic —C factor, D. Anti hemophilic — F factor', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]