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
Golden hour in thrombolytic therapy for cerebral stroke- 
Select and explain. 
A. 3 hrs, B. 6 hrs, C. 12 hrs, D. 24 hrs
A: 3 hrs
Answer: A: 3 hrs 
Explanation: None