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
[{'content': "True about blood transfusion -a) Antigen `D' determines Rh positivityb) Febrile reaction is due to HLA antibodiesc) Anti-D is naturally occuring antibodyd) Cryoprecipitate contains all coagulation factors \nSelect and explain. \nA. ac, B. a, C. ab, D. bc", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]