This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Pathology
[{'content': 'Acute graft rejection occurs within? \nSelect and explain. \nA. Few minutes, B. Few hours, C. < 6 months, D. 6-12 months', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Hyperacute rejection: type 2 HSR, happens over span of few minutes to hours. Eg: kidney transplant Acute rejection: Few weeks to months(< 6 months) Chronic rejection: After 6 months. Graft vs host disease (Runt Disease): Acute GVH: < 100 days Chronic GVH: > 100 days', 'role': 'assistant'}]