Final answer:
The best candidate for fibrinolytic therapy is the patient who had a thrombotic stroke and can receive treatment within 3 hours of the onset of symptoms.
Step-by-step explanation:
The best candidate for fibrinolytic therapy is the patient who had a thrombotic stroke and can receive treatment within 3 hours of the onset of symptoms. This is because thrombolytic agents can help break down the abnormal clot and improve the prognosis of the patient. In this case, the 50-year-old man who has slurred speech and left arm weakness that started 45 minutes ago and has a history of a heart attack is the most suitable candidate for fibrinolytic therapy.