You are answering a USMLE-style medical question. Question: A 57-year-old woman is brought to the emergency department by ambulance for dysarthria and left-sided facial droop. She is accompanied by her son, who states that the patient had just returned home an hour ago from walking the dog when suddenly the patient stated she felt “strange.” When her son asked her what was wrong, her speech was slurred and her "face looked funny.” The son quickly called an ambulance. The paramedic upon arrival noted that the patient had left-sided facial droop. Her medical history includes asthma and sickle cell disease. She takes hydroxyurea, uses oxycodone as needed for pain, and an albuterol inhaler as needed for shortness of breath. The patient’s temperature is 97°F (36.1°C), blood pressure is 145/72 mmHg, pulse is 93/min, and respirations are 14/min with an oxygen saturation of 96% on room air. On physical examination, a left-sided facial droop is appreciated. She has trouble articulating her words, and her speech is garbled. She is put on 2 L of oxygen by nasal cannula. Labs are obtained and pending. Which of the following therapies is most likely indicated? Options: A) Alteplase B) Exchange transfusion C) Hydralazine D) Warfarin Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.